Class SqlNode
- java.lang.Object
-
- org.apache.calcite.sql.SqlNode
-
- All Implemented Interfaces:
java.lang.Cloneable
- Direct Known Subclasses:
SqlCall
,SqlDataTypeSpec
,SqlDynamicParam
,SqlIdentifier
,SqlIntervalQualifier
,SqlLiteral
,SqlNodeList
public abstract class SqlNode extends java.lang.Object implements java.lang.Cloneable
ASqlNode
is a SQL parse tree.It may be an
operator
,literal
,identifier
, and so forth.
-
-
Field Summary
Fields Modifier and Type Field Description static SqlNode[]
EMPTY_ARRAY
protected SqlParserPos
pos
-
Constructor Summary
Constructors Constructor Description SqlNode(SqlParserPos pos)
Creates a node.
-
Method Summary
All Methods Static Methods Instance Methods Abstract Methods Concrete Methods Deprecated Methods Modifier and Type Method Description abstract <R> R
accept(SqlVisitor<R> visitor)
Accepts a generic visitor.java.lang.Object
clone()
Deprecated.Please useclone(SqlNode)
; this method brings along too much baggage from early versions of Javastatic <E extends SqlNode>
Eclone(E e)
Creates a copy of a SqlNode.abstract SqlNode
clone(SqlParserPos pos)
Clones a SqlNode with a different position.static SqlNode[]
cloneArray(SqlNode[] nodes)
Deprecated.static boolean
equalDeep(java.util.List<SqlNode> operands0, java.util.List<SqlNode> operands1, Litmus litmus)
Returns whether two lists of operands are equal.static boolean
equalDeep(SqlNode node1, SqlNode node2, Litmus litmus)
Returns whether two nodes are equal (usingequalsDeep(SqlNode, Litmus)
) or are both null.boolean
equalsDeep(SqlNode node, boolean fail)
Deprecated.abstract boolean
equalsDeep(SqlNode node, Litmus litmus)
Returns whether this node is structurally equivalent to another node.void
findValidOptions(SqlValidator validator, SqlValidatorScope scope, SqlParserPos pos, java.util.Collection<SqlMoniker> hintList)
Lists all the valid alternatives for this node if the parse position of the node matches that of pos.SqlKind
getKind()
Returns the type of node this is, orSqlKind.OTHER
if it's nothing special.SqlMonotonicity
getMonotonicity(SqlValidatorScope scope)
Returns whether expression is always ascending, descending or constant.SqlParserPos
getParserPosition()
boolean
isA(java.util.Set<SqlKind> category)
Returns whether this node is a member of an aggregate category.SqlString
toSqlString(SqlDialect dialect)
SqlString
toSqlString(SqlDialect dialect, boolean forceParens)
Returns the SQL text of the tree of which thisSqlNode
is the root.java.lang.String
toString()
abstract void
unparse(SqlWriter writer, int leftPrec, int rightPrec)
Writes a SQL representation of this node to a writer.abstract void
validate(SqlValidator validator, SqlValidatorScope scope)
Validates this node.void
validateExpr(SqlValidator validator, SqlValidatorScope scope)
Validates this node in an expression context.
-
-
-
Field Detail
-
EMPTY_ARRAY
public static final SqlNode[] EMPTY_ARRAY
-
pos
protected final SqlParserPos pos
-
-
Constructor Detail
-
SqlNode
SqlNode(SqlParserPos pos)
Creates a node.- Parameters:
pos
- Parser position, must not be null.
-
-
Method Detail
-
clone
@Deprecated public java.lang.Object clone()
Deprecated.Please useclone(SqlNode)
; this method brings along too much baggage from early versions of Java- Overrides:
clone
in classjava.lang.Object
-
clone
public static <E extends SqlNode> E clone(E e)
Creates a copy of a SqlNode.
-
clone
public abstract SqlNode clone(SqlParserPos pos)
Clones a SqlNode with a different position.
-
getKind
public SqlKind getKind()
Returns the type of node this is, orSqlKind.OTHER
if it's nothing special.- Returns:
- a
SqlKind
value, never null - See Also:
isA(java.util.Set<org.apache.calcite.sql.SqlKind>)
-
isA
public final boolean isA(java.util.Set<SqlKind> category)
Returns whether this node is a member of an aggregate category.For example,
node.isA(SqlKind.QUERY)
returnstrue
if the node is a SELECT, INSERT, UPDATE etc.This method is shorthand:
node.isA(category)
is always equivalent tonode.getKind().belongsTo(category)
.- Parameters:
category
- Category- Returns:
- Whether this node belongs to the given category.
-
toString
public java.lang.String toString()
- Overrides:
toString
in classjava.lang.Object
-
toSqlString
public SqlString toSqlString(SqlDialect dialect, boolean forceParens)
Returns the SQL text of the tree of which thisSqlNode
is the root.- Parameters:
dialect
- DialectforceParens
- wraps all expressions in parentheses; good for parse test, but false by default.Typical return values are:
- 'It''s a bird!'
- NULL
- 12.3
- DATE '1969-04-29'
-
toSqlString
public SqlString toSqlString(SqlDialect dialect)
-
unparse
public abstract void unparse(SqlWriter writer, int leftPrec, int rightPrec)
Writes a SQL representation of this node to a writer.The
leftPrec
andrightPrec
parameters give us enough context to decide whether we need to enclose the expression in parentheses. For example, we need parentheses around "2 + 3" if preceded by "5 *". This is because the precedence of the "*" operator is greater than the precedence of the "+" operator.The algorithm handles left- and right-associative operators by giving them slightly different left- and right-precedence.
If
SqlWriter.isAlwaysUseParentheses()
is true, we use parentheses even when they are not required by the precedence rules.For the details of this algorithm, see
SqlCall.unparse(org.apache.calcite.sql.SqlWriter, int, int)
.
-
getParserPosition
public SqlParserPos getParserPosition()
-
validate
public abstract void validate(SqlValidator validator, SqlValidatorScope scope)
Validates this node.The typical implementation of this method will make a callback to the validator appropriate to the node type and context. The validator has methods such as
SqlValidator.validateLiteral(org.apache.calcite.sql.SqlLiteral)
for these purposes.- Parameters:
scope
- Validator
-
findValidOptions
public void findValidOptions(SqlValidator validator, SqlValidatorScope scope, SqlParserPos pos, java.util.Collection<SqlMoniker> hintList)
Lists all the valid alternatives for this node if the parse position of the node matches that of pos. Only implemented now for SqlCall and SqlOperator.- Parameters:
validator
- Validatorscope
- Validation scopepos
- SqlParserPos indicating the cursor position at which completion hints are requested forhintList
- list of valid options
-
validateExpr
public void validateExpr(SqlValidator validator, SqlValidatorScope scope)
Validates this node in an expression context.Usually, this method does much the same as
validate(org.apache.calcite.sql.validate.SqlValidator, org.apache.calcite.sql.validate.SqlValidatorScope)
, but aSqlIdentifier
can occur in expression and non-expression contexts.
-
accept
public abstract <R> R accept(SqlVisitor<R> visitor)
Accepts a generic visitor.Implementations of this method in subtypes simply call the appropriate
visit
method on thevisitor object
.The type parameter
R
must be consistent with the type parameter of the visitor.
-
equalsDeep
public abstract boolean equalsDeep(SqlNode node, Litmus litmus)
Returns whether this node is structurally equivalent to another node. Some examples:- 1 + 2 is structurally equivalent to 1 + 2
- 1 + 2 + 3 is structurally equivalent to (1 + 2) + 3, but not to 1 + (2 + 3), because the '+' operator is left-associative
-
equalsDeep
@Deprecated public final boolean equalsDeep(SqlNode node, boolean fail)
Deprecated.
-
equalDeep
public static boolean equalDeep(SqlNode node1, SqlNode node2, Litmus litmus)
Returns whether two nodes are equal (usingequalsDeep(SqlNode, Litmus)
) or are both null.- Parameters:
node1
- First expressionnode2
- Second expressionlitmus
- What to do if an error is detected (expressions are not equal)
-
getMonotonicity
public SqlMonotonicity getMonotonicity(SqlValidatorScope scope)
Returns whether expression is always ascending, descending or constant. This property is useful because it allows to safely aggregate infinite streams of values.The default implementation returns
SqlMonotonicity.NOT_MONOTONIC
.- Parameters:
scope
- Scope
-
-