Package org.apache.calcite.sql

Class SqlSelectOperator

java.lang.Object

org.apache.calcite.sql.SqlOperator

org.apache.calcite.sql.SqlSelectOperator

public class SqlSelectOperator
extends SqlOperator

An operator describing a query. (Not a query itself.)

Operands are:

• 0: distinct (SqlLiteral)
• 1: selectClause (SqlNodeList)
• 2: fromClause (SqlCall to "join" operator)
• 3: whereClause (SqlNode)
• 4: havingClause (SqlNode)
• 5: groupClause (SqlNode)
• 6: windowClause (SqlNodeList)
• 7: orderClause (SqlNode)

Field Summary

Fields

Modifier and Type	Field	Description
static SqlSelectOperator	INSTANCE

Fields inherited from class org.apache.calcite.sql.SqlOperator

kind, MDX_PRECEDENCE, NL

Constructor Summary

Constructors

Modifier	Constructor	Description
private	SqlSelectOperator()

Method Summary

Modifier and Type	Method	Description
<R> void	acceptCall(SqlVisitor<R> visitor, SqlCall call, boolean onlyExpressions, SqlBasicVisitor.ArgHandler<R> argHandler)	Accepts a SqlVisitor, directing an SqlBasicVisitor.ArgHandler to visit an operand of a call.
boolean	argumentMustBeScalar(int ordinal)	Returns whether the ordinalth argument to this operator must be scalar (as opposed to a query).
SqlCall	createCall(SqlLiteral functionQualifier, SqlParserPos pos, SqlNode... operands)	Creates a call to this operand with an array of operands.
SqlSelect	createCall(SqlNodeList keywordList, SqlNodeList selectList, SqlNode fromClause, SqlNode whereClause, SqlNodeList groupBy, SqlNode having, SqlNodeList windowDecls, SqlNodeList orderBy, SqlNode offset, SqlNode fetch, SqlParserPos pos)	Creates a call to the SELECT operator.
SqlSyntax	getSyntax()	Returns the syntactic type of this operator, never null.
void	unparse(SqlWriter writer, SqlCall call, int leftPrec, int rightPrec)	Writes a SQL representation of a call to this operator to a writer, including parentheses if the operators on either side are of greater precedence.

Methods inherited from class org.apache.calcite.sql.SqlOperator

acceptCall, adjustType, allowsFraming, checkOperandCount, checkOperandTypes, constructArgNameList, constructArgTypeList, constructOperandList, createCall, createCall, createCall, deriveType, equals, getAllowedSignatures, getAllowedSignatures, getKind, getLeftPrec, getMonotonicity, getMonotonicity, getName, getNameAsId, getOperandCountRange, getOperandTypeChecker, getOperandTypeInference, getReturnTypeInference, getRightPrec, getSignatureTemplate, hashCode, inferReturnType, inferReturnType, isAggregator, isDeterministic, isDynamicFunction, isGroup, isGroupAuxiliary, isName, leftPrec, needsSpace, preValidateCall, requiresDecimalExpansion, requiresOrder, requiresOver, rewriteCall, rightPrec, toString, unparseListClause, unparseListClause, validateCall, validateOperands, validRexOperands

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

INSTANCE

public static final SqlSelectOperator INSTANCE

Constructor Detail

SqlSelectOperator

private SqlSelectOperator()

Method Detail

getSyntax

public SqlSyntax getSyntax()

Description copied from class: SqlOperator

Returns the syntactic type of this operator, never null.

Specified by:

getSyntax in class SqlOperator

createCall

public SqlCall createCall(SqlLiteral functionQualifier,
                          SqlParserPos pos,
                          SqlNode... operands)

Description copied from class: SqlOperator

Creates a call to this operand with an array of operands.

The position of the resulting call is the union of the pos and the positions of all of the operands.

Overrides:

createCall in class SqlOperator

Parameters:

functionQualifier - function qualifier (e.g. "DISTINCT"), may be

pos - parser position of the identifier of the call

operands - array of operands

createCall

public SqlSelect createCall(SqlNodeList keywordList,
                            SqlNodeList selectList,
                            SqlNode fromClause,
                            SqlNode whereClause,
                            SqlNodeList groupBy,
                            SqlNode having,
                            SqlNodeList windowDecls,
                            SqlNodeList orderBy,
                            SqlNode offset,
                            SqlNode fetch,
                            SqlParserPos pos)

Creates a call to the SELECT operator.

Parameters:

keywordList - List of keywords such DISTINCT and ALL, or null

selectList - The SELECT clause, or null if empty

fromClause - The FROM clause

whereClause - The WHERE clause, or null if not present

groupBy - The GROUP BY clause, or null if not present

having - The HAVING clause, or null if not present

windowDecls - The WINDOW clause, or null if not present

orderBy - The ORDER BY clause, or null if not present

offset - Expression for number of rows to discard before returning first row

fetch - Expression for number of rows to fetch

pos - The parser position, or SqlParserPos.ZERO if not specified; must not be null.

Returns:

A SqlSelect, never null

acceptCall

public <R> void acceptCall(SqlVisitor<R> visitor,
                           SqlCall call,
                           boolean onlyExpressions,
                           SqlBasicVisitor.ArgHandler<R> argHandler)

Description copied from class: SqlOperator

Accepts a SqlVisitor, directing an SqlBasicVisitor.ArgHandler to visit an operand of a call.

The argument handler allows fine control about how the operands are visited, and how the results are combined.

Overrides:

acceptCall in class SqlOperator

Parameters:

visitor - Visitor

call - Call to visit

onlyExpressions - If true, ignores operands which are not expressions. For example, in the call to the AS operator

argHandler - Called for each operand

unparse

public void unparse(SqlWriter writer,
                    SqlCall call,
                    int leftPrec,
                    int rightPrec)

Description copied from class: SqlOperator

Writes a SQL representation of a call to this operator to a writer, including parentheses if the operators on either side are of greater precedence.

The default implementation of this method delegates to SqlSyntax.unparse(org.apache.calcite.sql.SqlWriter, org.apache.calcite.sql.SqlOperator, org.apache.calcite.sql.SqlCall, int, int).

Overrides:

unparse in class SqlOperator

argumentMustBeScalar

public boolean argumentMustBeScalar(int ordinal)

Description copied from class: SqlOperator

Returns whether the ordinalth argument to this operator must be scalar (as opposed to a query).

If true (the default), the validator will attempt to convert the argument into a scalar sub-query, which must have one column and return at most one row.

Operators such as SELECT and EXISTS override this method.

Overrides:

argumentMustBeScalar in class SqlOperator