175897234Sdrh /* 2b19a2bc6Sdrh ** 2001 September 15 375897234Sdrh ** 4b19a2bc6Sdrh ** The author disclaims copyright to this source code. In place of 5b19a2bc6Sdrh ** a legal notice, here is a blessing: 675897234Sdrh ** 7b19a2bc6Sdrh ** May you do good and not evil. 8b19a2bc6Sdrh ** May you find forgiveness for yourself and forgive others. 9b19a2bc6Sdrh ** May you share freely, never taking more than you give. 1075897234Sdrh ** 1175897234Sdrh ************************************************************************* 1275897234Sdrh ** Internal interface definitions for SQLite. 1375897234Sdrh ** 14*a76b5dfcSdrh ** @(#) $Id: sqliteInt.h,v 1.90 2002/02/23 02:32:10 drh Exp $ 1575897234Sdrh */ 1675897234Sdrh #include "sqlite.h" 17beae3194Sdrh #include "hash.h" 1875897234Sdrh #include "vdbe.h" 1975897234Sdrh #include "parse.h" 20be0072d2Sdrh #include "btree.h" 2175897234Sdrh #include <stdio.h> 2275897234Sdrh #include <stdlib.h> 2375897234Sdrh #include <string.h> 2475897234Sdrh #include <assert.h> 2575897234Sdrh 26967e8b73Sdrh /* 27a1b351afSdrh ** The maximum number of in-memory pages to use for the main database 28a1b351afSdrh ** table and for temporary tables. 29a1b351afSdrh */ 30f57b14a6Sdrh #define MAX_PAGES 100 31f57b14a6Sdrh #define TEMP_PAGES 25 32a1b351afSdrh 33a1b351afSdrh /* 345a2c2c20Sdrh ** Integers of known sizes. These typedefs might change for architectures 355a2c2c20Sdrh ** where the sizes very. Preprocessor macros are available so that the 365a2c2c20Sdrh ** types can be conveniently redefined at compile-type. Like this: 375a2c2c20Sdrh ** 385a2c2c20Sdrh ** cc '-DUINTPTR_TYPE=long long int' ... 3941a2b48bSdrh */ 405a2c2c20Sdrh #ifndef UINT32_TYPE 415a2c2c20Sdrh # define UINT32_TYPE unsigned int 425a2c2c20Sdrh #endif 435a2c2c20Sdrh #ifndef UINT16_TYPE 445a2c2c20Sdrh # define UINT16_TYPE unsigned short int 455a2c2c20Sdrh #endif 465a2c2c20Sdrh #ifndef UINT8_TYPE 475a2c2c20Sdrh # define UINT8_TYPE unsigned char 485a2c2c20Sdrh #endif 495a2c2c20Sdrh #ifndef INTPTR_TYPE 505a2c2c20Sdrh # define INTPTR_TYPE int 515a2c2c20Sdrh #endif 525a2c2c20Sdrh typedef UINT32_TYPE u32; /* 4-byte unsigned integer */ 535a2c2c20Sdrh typedef UINT16_TYPE u16; /* 2-byte unsigned integer */ 545a2c2c20Sdrh typedef UINT8_TYPE u8; /* 1-byte unsigned integer */ 555a2c2c20Sdrh typedef INTPTR_TYPE ptr; /* Big enough to hold a pointer */ 565a2c2c20Sdrh typedef unsigned INTPTR_TYPE uptr; /* Big enough to hold a pointer */ 575a2c2c20Sdrh 585a2c2c20Sdrh /* 595a2c2c20Sdrh ** This macro casts a pointer to an integer. Useful for doing 605a2c2c20Sdrh ** pointer arithmetic. 615a2c2c20Sdrh */ 625a2c2c20Sdrh #define Addr(X) ((uptr)X) 6341a2b48bSdrh 6441a2b48bSdrh /* 65872ff86fSdrh ** The maximum number of bytes of data that can be put into a single 6680ff32f5Sdrh ** row of a single table. The upper bound on this limit is 16777215 6780ff32f5Sdrh ** bytes (or 16MB-1). We have arbitrarily set the limit to just 1MB 6880ff32f5Sdrh ** here because the overflow page chain is inefficient for really big 6980ff32f5Sdrh ** records and we want to discourage people from thinking that 7080ff32f5Sdrh ** multi-megabyte records are OK. If your needs are different, you can 7180ff32f5Sdrh ** change this define and recompile to increase or decrease the record 7280ff32f5Sdrh ** size. 73872ff86fSdrh */ 7480ff32f5Sdrh #define MAX_BYTES_PER_ROW 1048576 75872ff86fSdrh 76872ff86fSdrh /* 77967e8b73Sdrh ** If memory allocation problems are found, recompile with 78967e8b73Sdrh ** 79967e8b73Sdrh ** -DMEMORY_DEBUG=1 80967e8b73Sdrh ** 81967e8b73Sdrh ** to enable some sanity checking on malloc() and free(). To 82967e8b73Sdrh ** check for memory leaks, recompile with 83967e8b73Sdrh ** 84967e8b73Sdrh ** -DMEMORY_DEBUG=2 85967e8b73Sdrh ** 86967e8b73Sdrh ** and a line of text will be written to standard error for 87967e8b73Sdrh ** each malloc() and free(). This output can be analyzed 88967e8b73Sdrh ** by an AWK script to determine if there are any leaks. 89967e8b73Sdrh */ 90dcc581ccSdrh #ifdef MEMORY_DEBUG 91dcc581ccSdrh # define sqliteMalloc(X) sqliteMalloc_(X,__FILE__,__LINE__) 92dcc581ccSdrh # define sqliteFree(X) sqliteFree_(X,__FILE__,__LINE__) 93dcc581ccSdrh # define sqliteRealloc(X,Y) sqliteRealloc_(X,Y,__FILE__,__LINE__) 946e142f54Sdrh # define sqliteStrDup(X) sqliteStrDup_(X,__FILE__,__LINE__) 956e142f54Sdrh # define sqliteStrNDup(X,Y) sqliteStrNDup_(X,Y,__FILE__,__LINE__) 96c3c2fc9aSdrh void sqliteStrRealloc(char**); 97c3c2fc9aSdrh #else 98c3c2fc9aSdrh # define sqliteStrRealloc(X) 99dcc581ccSdrh #endif 100dcc581ccSdrh 10175897234Sdrh /* 102daffd0e5Sdrh ** This variable gets set if malloc() ever fails. After it gets set, 103daffd0e5Sdrh ** the SQLite library shuts down permanently. 104daffd0e5Sdrh */ 105daffd0e5Sdrh extern int sqlite_malloc_failed; 106daffd0e5Sdrh 107daffd0e5Sdrh /* 1086e142f54Sdrh ** The following global variables are used for testing and debugging 1098c82b350Sdrh ** only. They only work if MEMORY_DEBUG is defined. 1106e142f54Sdrh */ 1116e142f54Sdrh #ifdef MEMORY_DEBUG 1128c82b350Sdrh extern int sqlite_nMalloc; /* Number of sqliteMalloc() calls */ 1138c82b350Sdrh extern int sqlite_nFree; /* Number of sqliteFree() calls */ 1148c82b350Sdrh extern int sqlite_iMallocFail; /* Fail sqliteMalloc() after this many calls */ 1156e142f54Sdrh #endif 1166e142f54Sdrh 1176e142f54Sdrh /* 11875897234Sdrh ** Name of the master database table. The master database table 11975897234Sdrh ** is a special table that holds the names and attributes of all 12075897234Sdrh ** user tables and indices. 12175897234Sdrh */ 12275897234Sdrh #define MASTER_NAME "sqlite_master" 12375897234Sdrh 12475897234Sdrh /* 12575897234Sdrh ** A convenience macro that returns the number of elements in 12675897234Sdrh ** an array. 12775897234Sdrh */ 12875897234Sdrh #define ArraySize(X) (sizeof(X)/sizeof(X[0])) 12975897234Sdrh 13075897234Sdrh /* 131967e8b73Sdrh ** Integer identifiers for built-in SQL functions. 132cce7d176Sdrh */ 133cce7d176Sdrh #define FN_Unknown 0 134cce7d176Sdrh #define FN_Count 1 135cce7d176Sdrh #define FN_Min 2 136cce7d176Sdrh #define FN_Max 3 137cce7d176Sdrh #define FN_Sum 4 138cce7d176Sdrh #define FN_Avg 5 1390bdaf62eSdrh #define FN_Fcnt 6 1406ec2733bSdrh #define FN_Length 7 1416ec2733bSdrh #define FN_Substr 8 14281a20f21Sdrh #define FN_Abs 9 143bf4133cbSdrh #define FN_Round 10 144cce7d176Sdrh 145cce7d176Sdrh /* 14675897234Sdrh ** Forward references to structures 14775897234Sdrh */ 1487020f651Sdrh typedef struct Column Column; 14975897234Sdrh typedef struct Table Table; 15075897234Sdrh typedef struct Index Index; 15175897234Sdrh typedef struct Instruction Instruction; 15275897234Sdrh typedef struct Expr Expr; 15375897234Sdrh typedef struct ExprList ExprList; 15475897234Sdrh typedef struct Parse Parse; 15575897234Sdrh typedef struct Token Token; 15675897234Sdrh typedef struct IdList IdList; 15775897234Sdrh typedef struct WhereInfo WhereInfo; 1586b56344dSdrh typedef struct WhereLevel WhereLevel; 1599bb61fe7Sdrh typedef struct Select Select; 1602282792aSdrh typedef struct AggExpr AggExpr; 16175897234Sdrh 16275897234Sdrh /* 16375897234Sdrh ** Each database is an instance of the following structure 16475897234Sdrh */ 16575897234Sdrh struct sqlite { 1665e00f6c7Sdrh Btree *pBe; /* The B*Tree backend */ 167f57b3399Sdrh Btree *pBeTemp; /* Backend for session temporary tables */ 1688c82b350Sdrh int flags; /* Miscellanous flags. See below */ 1692803757aSdrh int file_format; /* What file format version is this database? */ 17050e5dadfSdrh int schema_cookie; /* Magic number that changes with the schema */ 17150e5dadfSdrh int next_cookie; /* Value of schema_cookie after commit */ 1722803757aSdrh int nTable; /* Number of tables in the database */ 1732dfbbcafSdrh void *pBusyArg; /* 1st Argument to the busy callback */ 174353f57e0Sdrh int (*xBusyCallback)(void *,const char*,int); /* The busy callback */ 175beae3194Sdrh Hash tblHash; /* All tables indexed by name */ 176beae3194Sdrh Hash idxHash; /* All (named) indices indexed by name */ 17774e24cd0Sdrh Hash tblDrop; /* Uncommitted DROP TABLEs */ 17874e24cd0Sdrh Hash idxDrop; /* Uncommitted DROP INDEXs */ 179af9ff33aSdrh int lastRowid; /* ROWID of most recent insert */ 1805cf8e8c7Sdrh int priorNewRowid; /* Last randomly generated ROWID */ 1811c92853dSdrh int onError; /* Default conflict algorithm */ 18275897234Sdrh }; 18375897234Sdrh 18475897234Sdrh /* 185967e8b73Sdrh ** Possible values for the sqlite.flags. 18675897234Sdrh */ 1874c504391Sdrh #define SQLITE_VdbeTrace 0x00000001 /* True to trace VDBE execution */ 1884c504391Sdrh #define SQLITE_Initialized 0x00000002 /* True after initialization */ 1894c504391Sdrh #define SQLITE_Interrupt 0x00000004 /* Cancel current operation */ 190c4a3c779Sdrh #define SQLITE_InTrans 0x00000008 /* True if in a transaction */ 1915e00f6c7Sdrh #define SQLITE_InternChanges 0x00000010 /* Uncommitted Hash table changes */ 192382c0247Sdrh #define SQLITE_FullColNames 0x00000020 /* Show full column names on SELECT */ 1931bee3d7bSdrh #define SQLITE_CountRows 0x00000040 /* Count rows changed by INSERT, */ 1941bee3d7bSdrh /* DELETE, or UPDATE and return */ 1951bee3d7bSdrh /* the count using a callback. */ 1966a535340Sdrh #define SQLITE_NullCallback 0x00000080 /* Invoke the callback once if the */ 1976a535340Sdrh /* result set is empty */ 198c3a64ba0Sdrh #define SQLITE_ResultDetails 0x00000100 /* Details added to result set */ 19958b9576bSdrh 20058b9576bSdrh /* 2012803757aSdrh ** Current file format version 2022803757aSdrh */ 2032803757aSdrh #define SQLITE_FileFormat 2 2042803757aSdrh 2052803757aSdrh /* 206967e8b73Sdrh ** information about each column of an SQL table is held in an instance 2077020f651Sdrh ** of this structure. 2087020f651Sdrh */ 2097020f651Sdrh struct Column { 2107020f651Sdrh char *zName; /* Name of this column */ 2117020f651Sdrh char *zDflt; /* Default value of this column */ 212382c0247Sdrh char *zType; /* Data type for this column */ 2134a32431cSdrh u8 notNull; /* True if there is a NOT NULL constraint */ 2144a32431cSdrh u8 isPrimKey; /* True if this column is an INTEGER PRIMARY KEY */ 2157020f651Sdrh }; 2167020f651Sdrh 2177020f651Sdrh /* 21822f70c32Sdrh ** Each SQL table is represented in memory by an instance of the 21922f70c32Sdrh ** following structure. 22022f70c32Sdrh ** 22122f70c32Sdrh ** Expr.zName is the name of the table. The case of the original 22222f70c32Sdrh ** CREATE TABLE statement is stored, but case is not significant for 22322f70c32Sdrh ** comparisons. 22422f70c32Sdrh ** 22522f70c32Sdrh ** Expr.nCol is the number of columns in this table. Expr.aCol is a 22622f70c32Sdrh ** pointer to an array of Column structures, one for each column. 22722f70c32Sdrh ** 22822f70c32Sdrh ** If the table has an INTEGER PRIMARY KEY, then Expr.iPKey is the index of 22922f70c32Sdrh ** the column that is that key. Otherwise Expr.iPKey is negative. Note 23022f70c32Sdrh ** that the datatype of the PRIMARY KEY must be INTEGER for this field to 23122f70c32Sdrh ** be set. An INTEGER PRIMARY KEY is used as the rowid for each row of 23222f70c32Sdrh ** the table. If a table has no INTEGER PRIMARY KEY, then a random rowid 23322f70c32Sdrh ** is generated for each row of the table. Expr.hasPrimKey is true if 23422f70c32Sdrh ** the table has any PRIMARY KEY, INTEGER or otherwise. 23522f70c32Sdrh ** 23622f70c32Sdrh ** Expr.tnum is the page number for the root BTree page of the table in the 23722f70c32Sdrh ** database file. If Expr.isTemp is true, then this page occurs in the 23822f70c32Sdrh ** auxiliary database file, not the main database file. If Expr.isTransient 23922f70c32Sdrh ** is true, then the table is stored in a file that is automatically deleted 24022f70c32Sdrh ** when the VDBE cursor to the table is closed. In this case Expr.tnum 24122f70c32Sdrh ** refers VDBE cursor number that holds the table open, not to the root 24222f70c32Sdrh ** page number. Transient tables are used to hold the results of a 24322f70c32Sdrh ** sub-query that appears instead of a real table name in the FROM clause 24422f70c32Sdrh ** of a SELECT statement. 24575897234Sdrh */ 24675897234Sdrh struct Table { 24775897234Sdrh char *zName; /* Name of the table */ 24875897234Sdrh int nCol; /* Number of columns in this table */ 2497020f651Sdrh Column *aCol; /* Information about each column */ 250c8392586Sdrh int iPKey; /* If not less then 0, use aCol[iPKey] as the primary key */ 251967e8b73Sdrh Index *pIndex; /* List of SQL indexes on this table. */ 25222f70c32Sdrh int tnum; /* Root BTree node for this table (see note above) */ 253*a76b5dfcSdrh Select *pSelect; /* NULL for tables. Points to definition if a view. */ 254717e6402Sdrh u8 readOnly; /* True if this table should not be written by the user */ 255717e6402Sdrh u8 isCommit; /* True if creation of this table has been committed */ 256f57b3399Sdrh u8 isTemp; /* True if stored in db->pBeTemp instead of db->pBe */ 25722f70c32Sdrh u8 isTransient; /* True if automatically deleted when VDBE finishes */ 2584a32431cSdrh u8 hasPrimKey; /* True if there exists a primary key */ 2599cfcf5d4Sdrh u8 keyConf; /* What to do in case of uniqueness conflict on iPKey */ 26075897234Sdrh }; 26175897234Sdrh 26275897234Sdrh /* 26322f70c32Sdrh ** SQLite supports 5 different ways to resolve a contraint 26422f70c32Sdrh ** error. ROLLBACK processing means that a constraint violation 2651c92853dSdrh ** causes the operation in proces to fail and for the current transaction 2661c92853dSdrh ** to be rolled back. ABORT processing means the operation in process 2671c92853dSdrh ** fails and any prior changes from that one operation are backed out, 2681c92853dSdrh ** but the transaction is not rolled back. FAIL processing means that 2691c92853dSdrh ** the operation in progress stops and returns an error code. But prior 2701c92853dSdrh ** changes due to the same operation are not backed out and no rollback 2711c92853dSdrh ** occurs. IGNORE means that the particular row that caused the constraint 2721c92853dSdrh ** error is not inserted or updated. Processing continues and no error 2731c92853dSdrh ** is returned. REPLACE means that preexisting database rows that caused 2741c92853dSdrh ** a UNIQUE constraint violation are removed so that the new insert or 2751c92853dSdrh ** update can proceed. Processing continues and no error is reported. 2761c92853dSdrh ** 2771c92853dSdrh ** The following there symbolic values are used to record which type 2781c92853dSdrh ** of action to take. 2799cfcf5d4Sdrh */ 2809cfcf5d4Sdrh #define OE_None 0 /* There is no constraint to check */ 2811c92853dSdrh #define OE_Rollback 1 /* Fail the operation and rollback the transaction */ 2821c92853dSdrh #define OE_Abort 2 /* Back out changes but do no rollback transaction */ 2831c92853dSdrh #define OE_Fail 3 /* Stop the operation but leave all prior changes */ 2841c92853dSdrh #define OE_Ignore 4 /* Ignore the error. Do not do the INSERT or UPDATE */ 2851c92853dSdrh #define OE_Replace 5 /* Delete existing record, then do INSERT or UPDATE */ 2869cfcf5d4Sdrh #define OE_Default 9 /* Do whatever the default action is */ 2879cfcf5d4Sdrh 2889cfcf5d4Sdrh /* 28966b89c8fSdrh ** Each SQL index is represented in memory by an 29075897234Sdrh ** instance of the following structure. 291967e8b73Sdrh ** 292967e8b73Sdrh ** The columns of the table that are to be indexed are described 293967e8b73Sdrh ** by the aiColumn[] field of this structure. For example, suppose 294967e8b73Sdrh ** we have the following table and index: 295967e8b73Sdrh ** 296967e8b73Sdrh ** CREATE TABLE Ex1(c1 int, c2 int, c3 text); 297967e8b73Sdrh ** CREATE INDEX Ex2 ON Ex1(c3,c1); 298967e8b73Sdrh ** 299967e8b73Sdrh ** In the Table structure describing Ex1, nCol==3 because there are 300967e8b73Sdrh ** three columns in the table. In the Index structure describing 301967e8b73Sdrh ** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed. 302967e8b73Sdrh ** The value of aiColumn is {2, 0}. aiColumn[0]==2 because the 303967e8b73Sdrh ** first column to be indexed (c3) has an index of 2 in Ex1.aCol[]. 304967e8b73Sdrh ** The second column to be indexed (c1) has an index of 0 in 305967e8b73Sdrh ** Ex1.aCol[], hence Ex2.aiColumn[1]==0. 30675897234Sdrh */ 30775897234Sdrh struct Index { 30875897234Sdrh char *zName; /* Name of this index */ 309967e8b73Sdrh int nColumn; /* Number of columns in the table used by this index */ 310967e8b73Sdrh int *aiColumn; /* Which columns are used by this index. 1st is 0 */ 311967e8b73Sdrh Table *pTable; /* The SQL table being indexed */ 312be0072d2Sdrh int tnum; /* Page containing root of this index in database file */ 3139cfcf5d4Sdrh u8 isUnique; /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */ 314717e6402Sdrh u8 isCommit; /* True if creation of this index has been committed */ 31574e24cd0Sdrh u8 isDropped; /* True if a DROP INDEX has executed on this index */ 3169cfcf5d4Sdrh u8 onError; /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */ 31775897234Sdrh Index *pNext; /* The next index associated with the same table */ 31875897234Sdrh }; 31975897234Sdrh 32075897234Sdrh /* 32175897234Sdrh ** Each token coming out of the lexer is an instance of 32275897234Sdrh ** this structure. 32375897234Sdrh */ 32475897234Sdrh struct Token { 32580ff32f5Sdrh const char *z; /* Text of the token. Not NULL-terminated! */ 32675897234Sdrh int n; /* Number of characters in this token */ 32775897234Sdrh }; 32875897234Sdrh 32975897234Sdrh /* 33075897234Sdrh ** Each node of an expression in the parse tree is an instance 33122f70c32Sdrh ** of this structure. 33222f70c32Sdrh ** 33322f70c32Sdrh ** Expr.op is the opcode. The integer parser token codes are reused 33422f70c32Sdrh ** as opcodes here. For example, the parser defines TK_GE to be an integer 33522f70c32Sdrh ** code representing the ">=" operator. This same integer code is reused 33622f70c32Sdrh ** to represent the greater-than-or-equal-to operator in the expression 33722f70c32Sdrh ** tree. 33822f70c32Sdrh ** 33922f70c32Sdrh ** Expr.pRight and Expr.pLeft are subexpressions. Expr.pList is a list 34022f70c32Sdrh ** of argument if the expression is a function. 34122f70c32Sdrh ** 34222f70c32Sdrh ** Expr.token is the operator token for this node. Expr.span is the complete 34322f70c32Sdrh ** subexpression represented by this node and all its decendents. These 34422f70c32Sdrh ** fields are used for error reporting and for reconstructing the text of 34522f70c32Sdrh ** an expression to use as the column name in a SELECT statement. 34622f70c32Sdrh ** 34722f70c32Sdrh ** An expression of the form ID or ID.ID refers to a column in a table. 34822f70c32Sdrh ** For such expressions, Expr.op is set to TK_COLUMN and Expr.iTable is 34922f70c32Sdrh ** the integer cursor number of a VDBE cursor pointing to that table and 35022f70c32Sdrh ** Expr.iColumn is the column number for the specific column. If the 35122f70c32Sdrh ** expression is used as a result in an aggregate SELECT, then the 35222f70c32Sdrh ** value is also stored in the Expr.iAgg column in the aggregate so that 35322f70c32Sdrh ** it can be accessed after all aggregates are computed. 35422f70c32Sdrh ** 35522f70c32Sdrh ** If the expression is a function, the Expr.iTable is an integer code 35622f70c32Sdrh ** representing which function. 35722f70c32Sdrh ** 35822f70c32Sdrh ** The Expr.pSelect field points to a SELECT statement. The SELECT might 35922f70c32Sdrh ** be the right operand of an IN operator. Or, if a scalar SELECT appears 36022f70c32Sdrh ** in an expression the opcode is TK_SELECT and Expr.pSelect is the only 36122f70c32Sdrh ** operand. 36275897234Sdrh */ 36375897234Sdrh struct Expr { 36475897234Sdrh int op; /* Operation performed by this node */ 36575897234Sdrh Expr *pLeft, *pRight; /* Left and right subnodes */ 36675897234Sdrh ExprList *pList; /* A list of expressions used as a function argument */ 36775897234Sdrh Token token; /* An operand token */ 368e1b6a5b8Sdrh Token span; /* Complete text of the expression */ 369967e8b73Sdrh int iTable, iColumn; /* When op==TK_COLUMN, then this expr node means the 370967e8b73Sdrh ** iColumn-th field of the iTable-th table. When 371967e8b73Sdrh ** op==TK_FUNCTION, iColumn holds the function id */ 372967e8b73Sdrh int iAgg; /* When op==TK_COLUMN and pParse->useAgg==TRUE, pull 373967e8b73Sdrh ** result from the iAgg-th element of the aggregator */ 37419a775c2Sdrh Select *pSelect; /* When the expression is a sub-select */ 37575897234Sdrh }; 37675897234Sdrh 37775897234Sdrh /* 37875897234Sdrh ** A list of expressions. Each expression may optionally have a 37975897234Sdrh ** name. An expr/name combination can be used in several ways, such 38075897234Sdrh ** as the list of "expr AS ID" fields following a "SELECT" or in the 38175897234Sdrh ** list of "ID = expr" items in an UPDATE. A list of expressions can 38275897234Sdrh ** also be used as the argument to a function, in which case the azName 38375897234Sdrh ** field is not used. 38475897234Sdrh */ 38575897234Sdrh struct ExprList { 38675897234Sdrh int nExpr; /* Number of expressions on the list */ 3876d4abfbeSdrh struct ExprList_item { 38875897234Sdrh Expr *pExpr; /* The list of expressions */ 38975897234Sdrh char *zName; /* Token associated with this expression */ 390d8bc7086Sdrh char sortOrder; /* 1 for DESC or 0 for ASC */ 391d8bc7086Sdrh char isAgg; /* True if this is an aggregate like count(*) */ 392d8bc7086Sdrh char done; /* A flag to indicate when processing is finished */ 39375897234Sdrh } *a; /* One entry for each expression */ 39475897234Sdrh }; 39575897234Sdrh 39675897234Sdrh /* 39775897234Sdrh ** A list of identifiers. 39875897234Sdrh */ 39975897234Sdrh struct IdList { 40075897234Sdrh int nId; /* Number of identifiers on the list */ 4016d4abfbeSdrh struct IdList_item { 40275897234Sdrh char *zName; /* Text of the identifier. */ 40375897234Sdrh char *zAlias; /* The "B" part of a "A AS B" phrase. zName is the "A" */ 404967e8b73Sdrh int idx; /* Index in some Table.aCol[] of a column named zName */ 405daffd0e5Sdrh Table *pTab; /* An SQL table corresponding to zName */ 406daffd0e5Sdrh Select *pSelect; /* A SELECT statement used in place of a table name */ 40775897234Sdrh } *a; /* One entry for each identifier on the list */ 40875897234Sdrh }; 40975897234Sdrh 41075897234Sdrh /* 4116b56344dSdrh ** For each nested loop in a WHERE clause implementation, the WhereInfo 4126b56344dSdrh ** structure contains a single instance of this structure. This structure 4136b56344dSdrh ** is intended to be private the the where.c module and should not be 4146b56344dSdrh ** access or modified by other modules. 4156b56344dSdrh */ 4166b56344dSdrh struct WhereLevel { 4176b56344dSdrh int iMem; /* Memory cell used by this level */ 4186b56344dSdrh Index *pIdx; /* Index used */ 4196b56344dSdrh int iCur; /* Cursor number used for this index */ 420487ab3caSdrh int score; /* How well this indexed scored */ 4216b56344dSdrh int brk; /* Jump here to break out of the loop */ 4226b56344dSdrh int cont; /* Jump here to continue with the next loop cycle */ 4236b56344dSdrh int op, p1, p2; /* Opcode used to terminate the loop */ 4246b56344dSdrh }; 4256b56344dSdrh 4266b56344dSdrh /* 42775897234Sdrh ** The WHERE clause processing routine has two halves. The 42875897234Sdrh ** first part does the start of the WHERE loop and the second 42975897234Sdrh ** half does the tail of the WHERE loop. An instance of 43075897234Sdrh ** this structure is returned by the first half and passed 43175897234Sdrh ** into the second half to give some continuity. 43275897234Sdrh */ 43375897234Sdrh struct WhereInfo { 43475897234Sdrh Parse *pParse; 43519a775c2Sdrh IdList *pTabList; /* List of tables in the join */ 43619a775c2Sdrh int iContinue; /* Jump here to continue with next record */ 43719a775c2Sdrh int iBreak; /* Jump here to break out of the loop */ 43819a775c2Sdrh int base; /* Index of first Open opcode */ 4396b56344dSdrh int nLevel; /* Number of nested loop */ 4406b56344dSdrh WhereLevel a[1]; /* Information about each nest loop in the WHERE */ 44175897234Sdrh }; 44275897234Sdrh 44375897234Sdrh /* 4449bb61fe7Sdrh ** An instance of the following structure contains all information 4459bb61fe7Sdrh ** needed to generate code for a single SELECT statement. 446*a76b5dfcSdrh ** 447*a76b5dfcSdrh ** The zSelect field is used when the Select structure must be persistent. 448*a76b5dfcSdrh ** Normally, the expression tree points to tokens in the original input 449*a76b5dfcSdrh ** string that encodes the select. But if the Select structure must live 450*a76b5dfcSdrh ** longer than its input string (for example when it is used to describe 451*a76b5dfcSdrh ** a VIEW) we have to make a copy of the input string so that the nodes 452*a76b5dfcSdrh ** of the expression tree will have something to point to. zSelect is used 453*a76b5dfcSdrh ** to hold that copy. 4549bb61fe7Sdrh */ 4559bb61fe7Sdrh struct Select { 4569bb61fe7Sdrh int isDistinct; /* True if the DISTINCT keyword is present */ 4579bb61fe7Sdrh ExprList *pEList; /* The fields of the result */ 4589bb61fe7Sdrh IdList *pSrc; /* The FROM clause */ 4599bb61fe7Sdrh Expr *pWhere; /* The WHERE clause */ 4609bb61fe7Sdrh ExprList *pGroupBy; /* The GROUP BY clause */ 4619bb61fe7Sdrh Expr *pHaving; /* The HAVING clause */ 4629bb61fe7Sdrh ExprList *pOrderBy; /* The ORDER BY clause */ 46382c3d636Sdrh int op; /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */ 464967e8b73Sdrh Select *pPrior; /* Prior select in a compound select statement */ 4659bbca4c1Sdrh int nLimit, nOffset; /* LIMIT and OFFSET values. -1 means not used */ 466*a76b5dfcSdrh char *zSelect; /* Complete text of the SELECT command */ 4679bb61fe7Sdrh }; 4689bb61fe7Sdrh 4699bb61fe7Sdrh /* 470fef5208cSdrh ** The results of a select can be distributed in several ways. 471fef5208cSdrh */ 472fef5208cSdrh #define SRT_Callback 1 /* Invoke a callback with each row of result */ 473fef5208cSdrh #define SRT_Mem 2 /* Store result in a memory cell */ 47482c3d636Sdrh #define SRT_Set 3 /* Store result as unique keys in a table */ 47582c3d636Sdrh #define SRT_Union 5 /* Store result as keys in a table */ 47682c3d636Sdrh #define SRT_Except 6 /* Remove result from a UNION table */ 4775974a30fSdrh #define SRT_Table 7 /* Store result as data with a unique key */ 478fef5208cSdrh 479fef5208cSdrh /* 4802282792aSdrh ** When a SELECT uses aggregate functions (like "count(*)" or "avg(f1)") 4812282792aSdrh ** we have to do some additional analysis of expressions. An instance 4822282792aSdrh ** of the following structure holds information about a single subexpression 4832282792aSdrh ** somewhere in the SELECT statement. An array of these structures holds 4842282792aSdrh ** all the information we need to generate code for aggregate 4852282792aSdrh ** expressions. 4862282792aSdrh ** 4872282792aSdrh ** Note that when analyzing a SELECT containing aggregates, both 4882282792aSdrh ** non-aggregate field variables and aggregate functions are stored 4892282792aSdrh ** in the AggExpr array of the Parser structure. 4902282792aSdrh ** 4912282792aSdrh ** The pExpr field points to an expression that is part of either the 4922282792aSdrh ** field list, the GROUP BY clause, the HAVING clause or the ORDER BY 4932282792aSdrh ** clause. The expression will be freed when those clauses are cleaned 4942282792aSdrh ** up. Do not try to delete the expression attached to AggExpr.pExpr. 4952282792aSdrh ** 4962282792aSdrh ** If AggExpr.pExpr==0, that means the expression is "count(*)". 4972282792aSdrh */ 4982282792aSdrh struct AggExpr { 4992282792aSdrh int isAgg; /* if TRUE contains an aggregate function */ 5002282792aSdrh Expr *pExpr; /* The expression */ 5012282792aSdrh }; 5022282792aSdrh 5032282792aSdrh /* 504f57b3399Sdrh ** An SQL parser context. A copy of this structure is passed through 505f57b3399Sdrh ** the parser and down into all the parser action routine in order to 506f57b3399Sdrh ** carry around information that is global to the entire parse. 50775897234Sdrh */ 50875897234Sdrh struct Parse { 50975897234Sdrh sqlite *db; /* The main database structure */ 5105e00f6c7Sdrh Btree *pBe; /* The database backend */ 5114c504391Sdrh int rc; /* Return code from execution */ 51275897234Sdrh sqlite_callback xCallback; /* The callback function */ 51375897234Sdrh void *pArg; /* First argument to the callback function */ 51475897234Sdrh char *zErrMsg; /* An error message */ 51575897234Sdrh Token sErrToken; /* The token at which the error occurred */ 51675897234Sdrh Token sFirstToken; /* The first token parsed */ 51775897234Sdrh Token sLastToken; /* The last token parsed */ 51875897234Sdrh Table *pNewTable; /* A table being constructed by CREATE TABLE */ 51975897234Sdrh Vdbe *pVdbe; /* An engine for executing database bytecode */ 520d8bc7086Sdrh int colNamesSet; /* TRUE after OP_ColumnCount has been issued to pVdbe */ 52175897234Sdrh int explain; /* True if the EXPLAIN flag is found on the query */ 52275897234Sdrh int initFlag; /* True if reparsing CREATE TABLEs */ 523f57b3399Sdrh int nameClash; /* A permanent table name clashes with temp table name */ 524d78eeee1Sdrh int newTnum; /* Table number to use when reparsing CREATE TABLEs */ 52575897234Sdrh int nErr; /* Number of errors seen */ 52619a775c2Sdrh int nTab; /* Number of previously allocated cursors */ 52719a775c2Sdrh int nMem; /* Number of memory cells used so far */ 528fef5208cSdrh int nSet; /* Number of sets used so far */ 5292282792aSdrh int nAgg; /* Number of aggregate expressions */ 5302282792aSdrh AggExpr *aAgg; /* An array of aggregate expressions */ 5312282792aSdrh int iAggCount; /* Index of the count(*) aggregate in aAgg[] */ 5322282792aSdrh int useAgg; /* If true, extract field values from the aggregator 5332282792aSdrh ** while generating expressions. Normally false */ 53450e5dadfSdrh int schemaVerified; /* True if an OP_VerifySchema has been coded someplace 53550e5dadfSdrh ** other than after an OP_Transaction */ 53675897234Sdrh }; 53775897234Sdrh 53875897234Sdrh /* 53975897234Sdrh ** Internal function prototypes 54075897234Sdrh */ 54175897234Sdrh int sqliteStrICmp(const char *, const char *); 54275897234Sdrh int sqliteStrNICmp(const char *, const char *, int); 54375897234Sdrh int sqliteHashNoCase(const char *, int); 54475897234Sdrh int sqliteCompare(const char *, const char *); 54575897234Sdrh int sqliteSortCompare(const char *, const char *); 5469bbca4c1Sdrh void sqliteRealToSortable(double r, char *); 547dcc581ccSdrh #ifdef MEMORY_DEBUG 548dcc581ccSdrh void *sqliteMalloc_(int,char*,int); 549dcc581ccSdrh void sqliteFree_(void*,char*,int); 550dcc581ccSdrh void *sqliteRealloc_(void*,int,char*,int); 5516e142f54Sdrh char *sqliteStrDup_(const char*,char*,int); 5526e142f54Sdrh char *sqliteStrNDup_(const char*, int,char*,int); 553dcc581ccSdrh #else 55475897234Sdrh void *sqliteMalloc(int); 55575897234Sdrh void sqliteFree(void*); 55675897234Sdrh void *sqliteRealloc(void*,int); 5576e142f54Sdrh char *sqliteStrDup(const char*); 5586e142f54Sdrh char *sqliteStrNDup(const char*, int); 559dcc581ccSdrh #endif 56075897234Sdrh void sqliteSetString(char **, const char *, ...); 56175897234Sdrh void sqliteSetNString(char **, ...); 562982cef7eSdrh void sqliteDequote(char*); 56317f71934Sdrh int sqliteKeywordCode(const char*, int); 56480ff32f5Sdrh int sqliteRunParser(Parse*, const char*, char **); 56575897234Sdrh void sqliteExec(Parse*); 56675897234Sdrh Expr *sqliteExpr(int, Expr*, Expr*, Token*); 567e1b6a5b8Sdrh void sqliteExprSpan(Expr*,Token*,Token*); 56875897234Sdrh Expr *sqliteExprFunction(ExprList*, Token*); 56975897234Sdrh void sqliteExprDelete(Expr*); 57075897234Sdrh ExprList *sqliteExprListAppend(ExprList*,Expr*,Token*); 57175897234Sdrh void sqliteExprListDelete(ExprList*); 572f57b14a6Sdrh void sqlitePragma(Parse*,Token*,Token*,int); 5735e00f6c7Sdrh void sqliteCommitInternalChanges(sqlite*); 5745e00f6c7Sdrh void sqliteRollbackInternalChanges(sqlite*); 575969fa7c1Sdrh Table *sqliteResultSetOfSelect(Parse*,char*,Select*); 576f57b3399Sdrh void sqliteStartTable(Parse*,Token*,Token*,int); 57775897234Sdrh void sqliteAddColumn(Parse*,Token*); 5789cfcf5d4Sdrh void sqliteAddNotNull(Parse*, int); 5799cfcf5d4Sdrh void sqliteAddPrimaryKey(Parse*, IdList*, int); 580382c0247Sdrh void sqliteAddColumnType(Parse*,Token*,Token*); 5817020f651Sdrh void sqliteAddDefaultValue(Parse*,Token*,int); 582969fa7c1Sdrh void sqliteEndTable(Parse*,Token*,Select*); 583*a76b5dfcSdrh void sqliteCreateView(Parse*,Token*,Token*,Select*); 58475897234Sdrh void sqliteDropTable(Parse*, Token*); 58575897234Sdrh void sqliteDeleteTable(sqlite*, Table*); 5869cfcf5d4Sdrh void sqliteInsert(Parse*, Token*, ExprList*, Select*, IdList*, int); 58775897234Sdrh IdList *sqliteIdListAppend(IdList*, Token*); 58875897234Sdrh void sqliteIdListAddAlias(IdList*, Token*); 58975897234Sdrh void sqliteIdListDelete(IdList*); 590717e6402Sdrh void sqliteCreateIndex(Parse*, Token*, Token*, IdList*, int, Token*, Token*); 59175897234Sdrh void sqliteDropIndex(Parse*, Token*); 59219a775c2Sdrh int sqliteSelect(Parse*, Select*, int, int); 5939bbca4c1Sdrh Select *sqliteSelectNew(ExprList*,IdList*,Expr*,ExprList*,Expr*,ExprList*, 5949bbca4c1Sdrh int,int,int); 5959bb61fe7Sdrh void sqliteSelectDelete(Select*); 596*a76b5dfcSdrh Table *sqliteTableNameToTable(Parse*, const char*); 597*a76b5dfcSdrh IdList *sqliteTableTokenToIdList(Parse*, Token*); 59875897234Sdrh void sqliteDeleteFrom(Parse*, Token*, Expr*); 5999cfcf5d4Sdrh void sqliteUpdate(Parse*, Token*, ExprList*, Expr*, int); 60075897234Sdrh WhereInfo *sqliteWhereBegin(Parse*, IdList*, Expr*, int); 60175897234Sdrh void sqliteWhereEnd(WhereInfo*); 60275897234Sdrh void sqliteExprCode(Parse*, Expr*); 60375897234Sdrh void sqliteExprIfTrue(Parse*, Expr*, int); 60475897234Sdrh void sqliteExprIfFalse(Parse*, Expr*, int); 605*a76b5dfcSdrh Table *sqliteFindTable(sqlite*,const char*); 606*a76b5dfcSdrh Index *sqliteFindIndex(sqlite*,const char*); 6076d4abfbeSdrh void sqliteUnlinkAndDeleteIndex(sqlite*,Index*); 608b419a926Sdrh void sqliteCopy(Parse*, Token*, Token*, Token*, int); 609dce2cbe6Sdrh void sqliteVacuum(Parse*, Token*); 610e17a7e33Sdrh int sqliteGlobCompare(const unsigned char*,const unsigned char*); 611dce2cbe6Sdrh int sqliteLikeCompare(const unsigned char*,const unsigned char*); 612cce7d176Sdrh char *sqliteTableNameFromToken(Token*); 613cce7d176Sdrh int sqliteExprCheck(Parse*, Expr*, int, int*); 614d8bc7086Sdrh int sqliteExprCompare(Expr*, Expr*); 615cce7d176Sdrh int sqliteFuncId(Token*); 616a2e00042Sdrh int sqliteExprResolveIds(Parse*, IdList*, ExprList*, Expr*); 6174794b980Sdrh void sqliteExprResolveInSelect(Parse*, Expr*); 6182282792aSdrh int sqliteExprAnalyzeAggregates(Parse*, Expr*); 619d8bc7086Sdrh Vdbe *sqliteGetVdbe(Parse*); 620b8ca307eSdrh int sqliteRandomByte(void); 621b8ca307eSdrh int sqliteRandomInteger(void); 6221c92853dSdrh void sqliteBeginTransaction(Parse*, int); 623c4a3c779Sdrh void sqliteCommitTransaction(Parse*); 624c4a3c779Sdrh void sqliteRollbackTransaction(Parse*); 625d1bf3512Sdrh char *sqlite_mprintf(const char *, ...); 6269208643dSdrh int sqliteExprIsConstant(Expr*); 6270ca3e24bSdrh void sqliteGenerateRowDelete(Vdbe*, Table*, int); 6280ca3e24bSdrh void sqliteGenerateRowIndexDelete(Vdbe*, Table*, int, char*); 6290ca3e24bSdrh void sqliteGenerateConstraintChecks(Parse*,Table*,int,char*,int,int,int,int); 630b419a926Sdrh void sqliteCompleteInsertion(Parse*, Table*, int, char*, int, int); 6311c92853dSdrh void sqliteBeginWriteOperation(Parse*); 632663fc63aSdrh void sqliteBeginMultiWriteOperation(Parse*); 6331c92853dSdrh void sqliteEndWriteOperation(Parse*); 634*a76b5dfcSdrh void sqliteExprMoveStrings(Expr*, int); 635*a76b5dfcSdrh void sqliteExprListMoveStrings(ExprList*, int); 636*a76b5dfcSdrh void sqliteSelectMoveStrings(Select*, int); 637