public SqlRexConvertlet get(SqlCall call) {
SqlRexConvertlet convertlet;
final SqlOperator op = call.getOperator();
// Is there a convertlet for this operator
// (e.g. SqlStdOperatorTable.plusOperator)?
convertlet = (SqlRexConvertlet) map.get(op);
if (convertlet != null) {
return convertlet;
}
// Is there a convertlet for this class of operator
// (e.g. SqlBinaryOperator)?
Class<? extends Object> clazz = op.getClass();
while (clazz != null) {
convertlet = (SqlRexConvertlet) map.get(clazz);
if (convertlet != null) {
return convertlet;
}
clazz = clazz.getSuperclass();
}
// Is there a convertlet for this class of expression
// (e.g. SqlCall)?
clazz = call.getClass();
while (clazz != null) {
convertlet = (SqlRexConvertlet) map.get(clazz);
if (convertlet != null) {
return convertlet;
}
clazz = clazz.getSuperclass();
}
return null;
}
public Void visit(SqlCall call) {
final SqlOperator operator = call.getOperator();
if (operator.isAggregator()) {
throw new Util.FoundOne(call);
}
// User-defined function may not be resolved yet.
if (operator instanceof SqlFunction
&& ((SqlFunction) operator).getFunctionType()
== SqlFunctionCategory.USER_DEFINED_FUNCTION) {
final List<SqlOperator> list = Lists.newArrayList();
opTab.lookupOperatorOverloads(
((SqlFunction) operator).getSqlIdentifier(),
SqlFunctionCategory.USER_DEFINED_FUNCTION,
SqlSyntax.FUNCTION,
list);
for (SqlOperator sqlOperator : list) {
if (sqlOperator.isAggregator()) {
throw new Util.FoundOne(call);
}
}
}
if (call.isA(SqlKind.QUERY)) {
// don't traverse into queries
return null;
}
if (call.getKind() == SqlKind.OVER) {
if (over) {
throw new Util.FoundOne(call);
} else {
// an aggregate function over a window is not an aggregate!
return null;
}
}
return super.visit(call);
}
private SqlNode createLeftCall(SqlOperator op, List<SqlNode> nodeList) {
if (nodeList.size() == 2) {
return op.createCall(new SqlNodeList(nodeList, POS));
}
final List<SqlNode> butLast = Util.skipLast(nodeList);
final SqlNode last = nodeList.get(nodeList.size() - 1);
final SqlNode call = createLeftCall(op, butLast);
return op.createCall(new SqlNodeList(ImmutableList.of(call, last), POS));
}
/** Converts a call to an aggregate function to an expression. */
public SqlNode toSql(AggregateCall aggCall) {
SqlOperator op = (SqlAggFunction) aggCall.getAggregation();
final List<SqlNode> operands = Expressions.list();
for (int arg : aggCall.getArgList()) {
operands.add(field(arg));
}
return op.createCall(
aggCall.isDistinct() ? SqlSelectKeyword.DISTINCT.symbol(POS) : null,
POS,
operands.toArray(new SqlNode[operands.size()]));
}
public void validateCall(
SqlCall call,
SqlValidator validator,
SqlValidatorScope scope,
SqlValidatorScope operandScope) {
// This implementation looks for the quantifier keywords DISTINCT or
// ALL as the first operand in the list. If found then the literal is
// not called to validate itself. Further the function is checked to
// make sure that a quantifier is valid for that particular function.
//
// If the first operand does not appear to be a quantifier then the
// parent ValidateCall is invoked to do normal function validation.
super.validateCall(call, validator, scope, operandScope);
validateQuantifier(validator, call);
}
public void unparse(
SqlWriter writer, SqlOperator operator, SqlCall call, int leftPrec, int rightPrec) {
assert call.operandCount() == 1;
call.operand(0).unparse(writer, operator.getLeftPrec(), operator.getRightPrec());
writer.keyword(operator.getName());
}
/** Converts an expression from {@link RexNode} to {@link SqlNode} format. */
SqlNode toSql(RexProgram program, RexNode rex) {
if (rex instanceof RexLocalRef) {
final int index = ((RexLocalRef) rex).getIndex();
return toSql(program, program.getExprList().get(index));
} else if (rex instanceof RexInputRef) {
return field(((RexInputRef) rex).getIndex());
} else if (rex instanceof RexLiteral) {
final RexLiteral literal = (RexLiteral) rex;
switch (literal.getTypeName().getFamily()) {
case CHARACTER:
return SqlLiteral.createCharString((String) literal.getValue2(), POS);
case NUMERIC:
case EXACT_NUMERIC:
return SqlLiteral.createExactNumeric(literal.getValue().toString(), POS);
case APPROXIMATE_NUMERIC:
return SqlLiteral.createApproxNumeric(literal.getValue().toString(), POS);
case BOOLEAN:
return SqlLiteral.createBoolean((Boolean) literal.getValue(), POS);
case DATE:
return SqlLiteral.createDate((Calendar) literal.getValue(), POS);
case TIME:
return SqlLiteral.createTime(
(Calendar) literal.getValue(), literal.getType().getPrecision(), POS);
case TIMESTAMP:
return SqlLiteral.createTimestamp(
(Calendar) literal.getValue(), literal.getType().getPrecision(), POS);
case ANY:
switch (literal.getTypeName()) {
case NULL:
return SqlLiteral.createNull(POS);
// fall through
}
default:
throw new AssertionError(literal + ": " + literal.getTypeName());
}
} else if (rex instanceof RexCall) {
final RexCall call = (RexCall) rex;
final SqlOperator op = call.getOperator();
final List<SqlNode> nodeList = toSql(program, call.getOperands());
if (op == SqlStdOperatorTable.CAST) {
RelDataType type = call.getType();
if (type.getSqlTypeName() == SqlTypeName.VARCHAR
&& dialect.getDatabaseProduct() == SqlDialect.DatabaseProduct.MYSQL) {
// MySQL doesn't have a VARCHAR type, only CHAR.
nodeList.add(
new SqlDataTypeSpec(
new SqlIdentifier("CHAR", POS), type.getPrecision(), -1, null, null, POS));
} else {
nodeList.add(toSql(type));
}
}
if (op == SqlStdOperatorTable.CASE) {
final SqlNode valueNode;
final List<SqlNode> whenList = Expressions.list();
final List<SqlNode> thenList = Expressions.list();
final SqlNode elseNode;
if (nodeList.size() % 2 == 0) {
// switched:
// "case x when v1 then t1 when v2 then t2 ... else e end"
valueNode = nodeList.get(0);
for (int i = 1; i < nodeList.size() - 1; i += 2) {
whenList.add(nodeList.get(i));
thenList.add(nodeList.get(i + 1));
}
} else {
// other: "case when w1 then t1 when w2 then t2 ... else e end"
valueNode = null;
for (int i = 0; i < nodeList.size() - 1; i += 2) {
whenList.add(nodeList.get(i));
thenList.add(nodeList.get(i + 1));
}
}
elseNode = nodeList.get(nodeList.size() - 1);
return op.createCall(
POS,
valueNode,
new SqlNodeList(whenList, POS),
new SqlNodeList(thenList, POS),
elseNode);
}
if (op instanceof SqlBinaryOperator && nodeList.size() > 2) {
// In RexNode trees, OR and AND have any number of children;
// SqlCall requires exactly 2. So, convert to a left-deep binary tree.
return createLeftCall(op, nodeList);
}
return op.createCall(new SqlNodeList(nodeList, POS));
} else {
throw new AssertionError(rex);
}
}