private Result(
SqlNode node,
Collection<Clause> clauses,
String neededAlias,
List<Pair<String, RelDataType>> aliases) {
this.node = node;
this.neededAlias = neededAlias;
this.aliases = aliases;
this.clauses = Expressions.list(clauses);
}
/** 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 RexNode toRex(Expression expression) {
switch (expression.getNodeType()) {
case MemberAccess:
return rexBuilder.makeFieldAccess(
toRex(((MemberExpression) expression).expression),
((MemberExpression) expression).field.getName());
case GreaterThan:
return binary(expression, SqlStdOperatorTable.greaterThanOperator);
case LessThan:
return binary(expression, SqlStdOperatorTable.lessThanOperator);
case Parameter:
return parameter((ParameterExpression) expression);
case Call:
MethodCallExpression call = (MethodCallExpression) expression;
SqlOperator operator = RexToLixTranslator.JAVA_TO_SQL_METHOD_MAP.get(call.method);
if (operator != null) {
return rexBuilder.makeCall(
operator,
toRex(
Expressions.<Expression>list()
.appendIfNotNull(call.targetExpression)
.appendAll(call.expressions)));
}
throw new RuntimeException("Could translate call to method " + call.method);
case Constant:
final ConstantExpression constant = (ConstantExpression) expression;
Object value = constant.value;
if (value instanceof Number) {
Number number = (Number) value;
if (value instanceof Double || value instanceof Float) {
return rexBuilder.makeApproxLiteral(BigDecimal.valueOf(number.doubleValue()));
} else if (value instanceof BigDecimal) {
return rexBuilder.makeExactLiteral((BigDecimal) value);
} else {
return rexBuilder.makeExactLiteral(BigDecimal.valueOf(number.longValue()));
}
} else if (value instanceof Boolean) {
return rexBuilder.makeLiteral((Boolean) value);
} else {
return rexBuilder.makeLiteral(constant.toString());
}
default:
throw new UnsupportedOperationException(
"unknown expression type " + expression.getNodeType() + " " + expression);
}
}
/**
* Once you have a Result of implementing a child relational expression, call this method to
* create a Builder to implement the current relational expression by adding additional clauses
* to the SQL query.
*
* <p>You need to declare which clauses you intend to add. If the clauses are "later", you can
* add to the same query. For example, "GROUP BY" comes after "WHERE". But if they are the same
* or earlier, this method will start a new SELECT that wraps the previous result.
*
* <p>When you have called {@link Builder#setSelect(org.eigenbase.sql.SqlNodeList)}, {@link
* Builder#setWhere(org.eigenbase.sql.SqlNode)} etc. call {@link
* Builder#result(org.eigenbase.sql.SqlNode, java.util.Collection, org.eigenbase.rel.RelNode)}
* to fix the new query.
*
* @param rel Relational expression being implemented
* @param clauses Clauses that will be generated to implement current relational expression
* @return A builder
*/
public Builder builder(JdbcRel rel, Clause... clauses) {
final Clause maxClause = maxClause();
boolean needNew = false;
for (Clause clause : clauses) {
if (maxClause.ordinal() >= clause.ordinal()) {
needNew = true;
}
}
SqlSelect select;
Expressions.FluentList<Clause> clauseList = Expressions.list();
if (needNew) {
select = subSelect();
} else {
select = asSelect();
clauseList.addAll(this.clauses);
}
clauseList.addAll(Arrays.asList(clauses));
Context newContext;
final SqlNodeList selectList = select.getSelectList();
if (selectList != null) {
newContext =
new Context(selectList.size()) {
@Override
public SqlNode field(int ordinal) {
final SqlNode selectItem = selectList.get(ordinal);
switch (selectItem.getKind()) {
case AS:
return ((SqlCall) selectItem).operand(0);
}
return selectItem;
}
};
} else {
newContext = new AliasContext(aliases, aliases.size() > 1);
}
return new Builder(rel, clauseList, select, newContext);
}
/**
* Creates a result based on a join. (Each join could contain one or more relational expressions.)
*/
public Result result(SqlNode join, Result leftResult, Result rightResult) {
final List<Pair<String, RelDataType>> list = new ArrayList<Pair<String, RelDataType>>();
list.addAll(leftResult.aliases);
list.addAll(rightResult.aliases);
return new Result(join, Expressions.list(Clause.FROM), null, list);
}
/** 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);
}
}