/**
* Generates code to cast an OJ expression as another type. See class description for an
* explanation of arguments.
*
* @return resulting expression. If lhsExp was provided, assigns this expression to lhsExp.
*/
public Expression convertCastOrAssignment(
FarragoRexToOJTranslator translator,
StatementList stmtList,
String targetName,
RelDataType lhsType,
RelDataType rhsType,
Expression lhsExp,
Expression rhsExp) {
CastHelper helper =
new CastHelper(translator, stmtList, targetName, lhsType, rhsType, lhsExp, rhsExp);
return helper.implement();
}
// implement FarragoOJRexImplementor
public Expression implementFarrago(
FarragoRexToOJTranslator translator, RexCall call, Expression[] operands) {
RelDataType lhsType = call.getType();
RelDataType rhsType = call.operands[0].getType();
Expression rhsExp = operands[0];
SqlTypeName lhsTypeName = lhsType.getSqlTypeName();
if ((lhsTypeName == SqlTypeName.CURSOR) || (lhsTypeName == SqlTypeName.COLUMN_LIST)) {
// Conversion should already have been taken care of outside.
return rhsExp;
}
// NOTE jvs 19-Nov-2008: In some cases (e.g. FRG-273) a cast
// may be illegal at the SQL level, but allowable as part of
// implementation, so don't try to enforce
// SqlTypeUtil.canCastFrom here. Anything which was supposed
// to have been prevented should already have been caught
// by the validator.
CastHelper helper =
new CastHelper(translator, null, call.toString(), lhsType, rhsType, null, rhsExp);
return helper.implement();
}