Class MapIsEmptyMethod

java.lang.Object
org.datanucleus.store.rdbms.sql.method.MapIsEmptyMethod
All Implemented Interfaces:
SQLMethod

public class MapIsEmptyMethod extends Object implements SQLMethod
Method for evaluating {mapExpr}.isEmpty(). Returns a BooleanExpression, utilising the size() expression. So the SQL will be something like
 (SELECT COUNT(*) FROM MAPTABLE A0_SUB WHERE A0_SUB.OWNER_ID_OID = A0.OWNER_ID) = 0
 
  • Constructor Details

    • MapIsEmptyMethod

      public MapIsEmptyMethod()
  • Method Details

    • getExpression

      public SQLExpression getExpression(SQLStatement stmt, SQLExpression expr, List<SQLExpression> args)
      Description copied from interface: SQLMethod
      Return the expression for this SQL function.
      Specified by:
      getExpression in interface SQLMethod
      Parameters:
      stmt - SQLStatement that this expression is for
      expr - The expression that it is invoked on
      args - Arguments passed in
      Returns:
      The SQL expression using the SQL function