/**
* Generates a cast for a row type.
*
* @param rexBuilder RexBuilder to use for constructing casts
* @param lhsRowType target row type
* @param rhsExps expressions to be cast
* @return cast expressions
*/
public static RexNode[] generateCastExpressions(
RexBuilder rexBuilder, RelDataType lhsRowType, RexNode[] rhsExps) {
RelDataTypeField[] lhsFields = lhsRowType.getFields();
final int fieldCount = lhsFields.length;
RexNode[] castExps = new RexNode[fieldCount];
assert fieldCount == rhsExps.length;
for (int i = 0; i < fieldCount; ++i) {
RelDataTypeField lhsField = lhsFields[i];
RelDataType lhsType = lhsField.getType();
RelDataType rhsType = rhsExps[i].getType();
if (lhsType.equals(rhsType)) {
castExps[i] = rhsExps[i];
} else {
castExps[i] = rexBuilder.makeCast(lhsType, rhsExps[i]);
}
}
return castExps;
}
