Class GetCurrentConnectionNode
- java.lang.Object
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- org.apache.derby.impl.sql.compile.QueryTreeNode
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- org.apache.derby.impl.sql.compile.JavaValueNode
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- org.apache.derby.impl.sql.compile.GetCurrentConnectionNode
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- All Implemented Interfaces:
Visitable
public final class GetCurrentConnectionNode extends JavaValueNode
This node represents a unary getCurrentConnection operator RESOLVE - parameter will always be null for now. Someday we may want to allow user to specify which of their connections they want. Assume that we will use a String.
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Field Summary
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Fields inherited from class org.apache.derby.impl.sql.compile.JavaValueNode
forCallStatement, jsqlType
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Fields inherited from class org.apache.derby.impl.sql.compile.QueryTreeNode
AUTOINCREMENT_CREATE_MODIFY, AUTOINCREMENT_CYCLE, AUTOINCREMENT_INC_INDEX, AUTOINCREMENT_IS_AUTOINCREMENT_INDEX, AUTOINCREMENT_START_INDEX
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Constructor Summary
Constructors Constructor Description GetCurrentConnectionNode(ContextManager cm)
Constructor for a GetCurrentConnectionNode
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description (package private) JavaValueNode
bindExpression(FromList fromList, SubqueryList subqueryList, java.util.List<AggregateNode> aggregates)
Bind this operator(package private) void
bindParameter()
Bind a ?(package private) boolean
categorize(JBitSet referencedTabs, boolean simplePredsOnly)
Categorize this predicate.(package private) void
checkReliability(ValueNode sqlNode)
Check the reliability type of this java value.(package private) void
generateExpression(ExpressionClassBuilder acb, MethodBuilder mb)
General logic shared by Core compilation and by the Replication Filter compiler.(package private) int
getOrderableVariantType()
Return the variant type for the underlying expression.(package private) void
preprocess(int numTables, FromList outerFromList, SubqueryList outerSubqueryList, PredicateList outerPredicateList)
Preprocess an expression tree.(package private) JavaValueNode
remapColumnReferencesToExpressions()
Remap all ColumnReferences in this tree to be clones of the underlying expression.-
Methods inherited from class org.apache.derby.impl.sql.compile.JavaValueNode
castToPrimitive, generate, generateReceiver, generateReceiver, getCollationType, getConstantValueAsObject, getDataType, getJavaTypeName, getJSQLType, getPrimitiveTypeName, getReceiverExpression, isPrimitiveType, mapToTypeID, markForCallStatement, markReturnValueDiscarded, mustCastToPrimitive, returnValueDiscarded, returnValueToSQLDomain, setCollationType, setJavaTypeName, valueReturnedToSQLDomain
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Methods inherited from class org.apache.derby.impl.sql.compile.QueryTreeNode
accept, acceptChildren, addTag, addUDTUsagePriv, addUDTUsagePriv, bindOffsetFetch, bindRowMultiSet, bindUserCatalogType, bindUserType, checkReliability, checkReliability, convertDefaultNode, copyTagsFrom, createTypeDependency, debugFlush, debugPrint, disablePrivilegeCollection, formatNodeString, generateAuthorizeCheck, getBeginOffset, getClassFactory, getCompilerContext, getContext, getContextManager, getDataDictionary, getDependencyManager, getEndOffset, getExecutionFactory, getGenericConstantActionFactory, getIntProperty, getLanguageConnectionContext, getLongProperty, getNullNode, getOffsetOrderedNodes, getOptimizerFactory, getOptimizerTracer, getParameterTypes, getSchemaDescriptor, getSchemaDescriptor, getStatementType, getTableDescriptor, getTypeCompiler, getUDTDesc, isAtomic, isPrivilegeCollectionRequired, isSessionSchema, isSessionSchema, makeConstantAction, makeTableName, makeTableName, nodeHeader, optimizerTracingIsOn, orReliability, parseSearchCondition, parseStatement, printLabel, printSubNodes, referencesSessionSchema, resolveTableToSynonym, setBeginOffset, setEndOffset, setRefActionInfo, stackPrint, taggedWith, toString, treePrint, treePrint, verifyClassExist
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Constructor Detail
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GetCurrentConnectionNode
GetCurrentConnectionNode(ContextManager cm)
Constructor for a GetCurrentConnectionNode
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Method Detail
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bindExpression
JavaValueNode bindExpression(FromList fromList, SubqueryList subqueryList, java.util.List<AggregateNode> aggregates) throws StandardException
Bind this operator- Specified by:
bindExpression
in classJavaValueNode
- Parameters:
fromList
- The query's FROM listsubqueryList
- The subquery list being built as we find SubqueryNodesaggregates
- The aggregate list being built as we find AggregateNodes- Returns:
- the new node, usually this
- Throws:
StandardException
- Thrown on error- See Also:
ValueNode.bindExpression(org.apache.derby.impl.sql.compile.FromList, org.apache.derby.impl.sql.compile.SubqueryList, java.util.List<org.apache.derby.impl.sql.compile.AggregateNode>)
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preprocess
void preprocess(int numTables, FromList outerFromList, SubqueryList outerSubqueryList, PredicateList outerPredicateList) throws StandardException
Preprocess an expression tree. We do a number of transformations here (including subqueries, IN lists, LIKE and BETWEEN) plus subquery flattening. NOTE: This is done before the outer ResultSetNode is preprocessed.- Specified by:
preprocess
in classJavaValueNode
- Parameters:
numTables
- Number of tables in the DML StatementouterFromList
- FromList from outer query blockouterSubqueryList
- SubqueryList from outer query blockouterPredicateList
- PredicateList from outer query block- Throws:
StandardException
- Thrown on error- See Also:
ValueNode.preprocess(int, org.apache.derby.impl.sql.compile.FromList, org.apache.derby.impl.sql.compile.SubqueryList, org.apache.derby.impl.sql.compile.PredicateList)
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categorize
boolean categorize(JBitSet referencedTabs, boolean simplePredsOnly)
Categorize this predicate. Initially, this means building a bit map of the referenced tables for each predicate. If the source of this ColumnReference (at the next underlying level) is not a ColumnReference or a VirtualColumnNode then this predicate will not be pushed down. For example, in: select * from (select 1 from s) a (x) where x = 1 we will not push down x = 1. NOTE: It would be easy to handle the case of a constant, but if the inner SELECT returns an arbitrary expression, then we would have to copy that tree into the pushed predicate, and that tree could contain subqueries and method calls. RESOLVE - revisit this issue once we have views.- Specified by:
categorize
in classJavaValueNode
- Parameters:
referencedTabs
- JBitSet with bit map of referenced FromTablessimplePredsOnly
- Whether or not to consider method calls, field references and conditional nodes when building bit map- Returns:
- boolean Whether or not source.expression is a ColumnReference or a VirtualColumnNode.
- See Also:
ValueNode.categorize(org.apache.derby.iapi.util.JBitSet, boolean)
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remapColumnReferencesToExpressions
JavaValueNode remapColumnReferencesToExpressions()
Remap all ColumnReferences in this tree to be clones of the underlying expression.- Specified by:
remapColumnReferencesToExpressions
in classJavaValueNode
- Returns:
- JavaValueNode The remapped expression tree.
- See Also:
ValueNode.remapColumnReferencesToExpressions()
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bindParameter
void bindParameter()
Bind a ? parameter operand of the char_length function.
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getOrderableVariantType
int getOrderableVariantType()
Return the variant type for the underlying expression. The variant type can be: VARIANT - variant within a scan (method calls and non-static field access) SCAN_INVARIANT - invariant within a scan (column references from outer tables) QUERY_INVARIANT - invariant within the life of a query (constant expressions)- Overrides:
getOrderableVariantType
in classJavaValueNode
- Returns:
- The variant type for the underlying expression.
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generateExpression
void generateExpression(ExpressionClassBuilder acb, MethodBuilder mb) throws StandardException
Description copied from class:JavaValueNode
General logic shared by Core compilation and by the Replication Filter compiler. Every child of ValueNode must implement one of these methods.- Specified by:
generateExpression
in classJavaValueNode
- Parameters:
acb
- The ExpressionClassBuilder for the class being builtmb
- The method the code to place the code- Throws:
StandardException
- Thrown on error- See Also:
ConstantNode.generateExpression(org.apache.derby.impl.sql.compile.ExpressionClassBuilder, org.apache.derby.iapi.services.compiler.MethodBuilder)
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checkReliability
void checkReliability(ValueNode sqlNode) throws StandardException
Check the reliability type of this java value.- Overrides:
checkReliability
in classJavaValueNode
- Throws:
StandardException
- Thrown on error- See Also:
CompilerContext
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