Lines Matching refs:is

12 The "x" is referred to as the LHS (left-hand side).  The list or subquery
13 on the right is called the RHS (right-hand side).  If the RHS is a list
14 it must be a non-empty list.  But if the RHS is a subquery, it can be an
21 a subquery that returns a single columns is called a scalar.
24 that returns two or more columns, or a list of scalars.  It is not
28 the RHS.  If the RHS is a list of values, then the LHS must be a 
29 scalar.  If the RHS is a subquery returning N columns, then the LHS
34 NULL values then we say that it is a "total-NULL".  If the LHS contains
35 some NULL values and some non-NULL values, then it is a "partial-NULL".
36 For a scalar, there is no difference between a partial-NULL and a total-NULL.
37 The RHS is a partial-NULL if any row contains a NULL value.  The RHS is
39 The LHS is called "non-NULL" if it contains no NULL values.  The RHS is
42 The result of an IN operator is one of TRUE, FALSE, or NULL.  A NULL result
43 means that it cannot be determined if the LHS is contained in the RHS due
49 the FALSE/NOT-FALSE binary is needed, we have to compute the three-state
53 A "NOT IN" operator is computed by first computing the equivalent IN
59 algorithm is suboptimal, especially if there are many rows on the RHS.
66       <li>  If the comparison result is NULL, set the null-flag to true
68   3.  If the null-flag is true, return NULL.
75 is the algorithm that is implemented in SQLite.
77   1.  If the RHS is a constant list of length 1 or 2, then rewrite the
86       This is the INDEX_NOOP optimization and is only undertaken if the
87       IN operator is used for membership testing.  If the IN operator is
90   2.  Check the LHS to see if it is a partial-NULL and if it is, jump
94       an exact match is found, return TRUE.
96   4.  If the RHS is non-NULL then return FALSE.
102       if the result is NULL, immediately return NULL.  In the case
105       first.  If the RHS is empty, this step is a no-op.