Syntax
… { {operand1 {=|EQ|<>|NE|>|GT|<|LT|>=|GE|<=|LE}
{ operand2
| {[ALL|ANY|SOME] ( SELECT subquery_clauses [ UNION …] )} }}
| {operand [NOT] BETWEEN operand1 AND operand2}
| {operand1 [NOT] LIKE operand2 [ESCAPE esc]}
| {operand [NOT] IN (operand1, operand2 …)}
| {operand [NOT] IN @seltab}
| {operand IS [NOT] NULL}
| {(cond_syntax)}
| { EXISTS ( SELECT subquery_clauses [UNION …] )}
| {operand [NOT] IN ( SELECT subquery_clauses [UNION …] )} } …
Effect
Relational expression in a condition of an Open SQL statement. Logical expressions sql_cond can be formed from the relational expressions shown here for the following conditions:
大意：在Open SQL条件中关系表达式。
Read accesses
WHERE clause of a query
HAVING clause of a query
ON condition of a join expression
Modifying accesses
WHERE condition of the statement UPDATE
WHERE condition of the statement DELETE
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