MULTEXT - Document MQL2. SgmlQL reference/Operators.
Exists

The operator exists...in returns TRUE if

the query boolean is true.

Prototype

boolean <-- exists variable1 in list1
[, variable2 in list2]*
: boolean

Examples

  • exists $d in (top DATE within file $myfile): text($d) match "1992";
  • TRUE

    Note that the evaluation stops at the first tuple for which boolean is true. The computation can be expensive for large lists, since in the worst case, the entire cartesian product of list1, list2, etc. is computed.



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