public class SqlDescribeSchema extends SqlCall
SqlDescribeSchema
is a node of a parse tree that represents a
DESCRIBE SCHEMA
statement.Modifier and Type | Field and Description |
---|---|
static SqlSpecialOperator |
OPERATOR |
(package private) SqlIdentifier |
schema |
EMPTY_ARRAY, pos
Constructor and Description |
---|
SqlDescribeSchema(SqlParserPos pos,
SqlIdentifier schema)
Creates a SqlDescribeSchema.
|
Modifier and Type | Method and Description |
---|---|
java.util.List<SqlNode> |
getOperandList() |
SqlOperator |
getOperator() |
SqlIdentifier |
getSchema() |
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
public static final SqlSpecialOperator OPERATOR
SqlIdentifier schema
public SqlDescribeSchema(SqlParserPos pos, SqlIdentifier schema)
public 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)
.
public void setOperand(int i, SqlNode operand)
SqlCall
SqlValidator
; use sparingly.setOperand
in class SqlCall
i
- Operand indexoperand
- Operand valuepublic SqlOperator getOperator()
getOperator
in class SqlCall
public java.util.List<SqlNode> getOperandList()
getOperandList
in class SqlCall
public SqlIdentifier getSchema()
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