public class SqlSnapshot extends SqlCall
FOR SYSTEM_TIME AS OF
" temporal clause.Modifier and Type | Class and Description |
---|---|
static class |
SqlSnapshot.SqlSnapshotOperator
An operator describing a FOR SYSTEM_TIME specification.
|
Modifier and Type | Field and Description |
---|---|
private static int |
OPERAND_PERIOD |
private static int |
OPERAND_TABLE_REF |
private SqlNode |
period |
private SqlNode |
tableRef |
EMPTY_ARRAY, pos
Constructor and Description |
---|
SqlSnapshot(SqlParserPos pos,
SqlNode tableRef,
SqlNode period)
Creates a SqlSnapshot.
|
Modifier and Type | Method and Description |
---|---|
java.util.List<SqlNode> |
getOperandList() |
SqlOperator |
getOperator() |
SqlNode |
getPeriod() |
SqlNode |
getTableRef() |
void |
setOperand(int i,
SqlNode operand)
Changes the value of an operand.
|
void |
unparse(SqlWriter writer,
int leftPrec,
int rightPrec)
Writes a SQL representation of this node to a writer.
|
accept, clone, equalsDeep, findValidOptions, getCallSignature, getFunctionQuantifier, getKind, getMonotonicity, isCountStar, isExpanded, operand, operandCount, validate
clone, clone, cloneArray, equalDeep, equalDeep, equalsDeep, getParserPosition, isA, toSqlString, toSqlString, toString, validateExpr
private static final int OPERAND_TABLE_REF
private static final int OPERAND_PERIOD
private SqlNode tableRef
private SqlNode period
public SqlSnapshot(SqlParserPos pos, SqlNode tableRef, SqlNode period)
public SqlOperator getOperator()
getOperator
in class SqlCall
public java.util.List<SqlNode> getOperandList()
getOperandList
in class SqlCall
public SqlNode getTableRef()
public SqlNode getPeriod()
public void setOperand(int i, SqlNode operand)
SqlCall
SqlValidator
; use sparingly.setOperand
in class SqlCall
i
- Operand indexoperand
- Operand valuepublic void unparse(SqlWriter writer, int leftPrec, int rightPrec)
SqlNode
The leftPrec
and rightPrec
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)
.
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