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Conditional question structure also checks the existence of records with it ? RRS feed

  • Question

  • In the access: Ask how the conditional questioning problem with the condition checks the existence of that message, for example I have the following problem:
    [CODE]
    SELECT    FIELD1, FIELD2, FIELD_EXPRESSION1, FIELD_EXPRESSION2
    FROM         TABLE
    WHERE     CONDITION
    [/CODE]

    Inside: 
    FIELD1, FIELD2: this is field of table
    FIELD_EXPRESSION1, FIELD_EXPRESSION2: this is expression and conditional query

    [CODE]
    FIELD_EXPRESSION =

    SELECT *
    FROM TABLE
    WHERE EXISTS (
      SELECT NULL
      FROM TABLE AS TABLE_2
      WHERE (CONDITION)  
    );
    [/CODE]

    When writing this type of problem, I has an error because we do not know how to believe the existence of that child record (only table), how to write the form file on the problem structure ?
    Saturday, March 23, 2019 5:04 AM