org.apache.derby.impl.sql.compile

An activation class is defined for each statement.

A NULL from the parser may not yet know its type; that must be set during binding, as it is for parameters.

the DataValueDescriptor methods want to throw exceptions when they are of the wrong type, but to do that they must check typeId when the value is null, rather than the instanceof check they do for returning a valid value.

For code generation, we generate a static field.

After parsing, the node contains targetTableName: the target table for the insert collist: a list of column names, if specified queryexpr: the expression being inserted, either a values clause or a select form; both of these are represented via the SelectNode, potentially with a TableOperatorNode such as UnionNode above it.

After binding, the node has had the target table's descriptor located and inserted, and the queryexpr and collist have been massaged so that they are identical to the table layout.

Functions supported:

• USER
• CURRENT_USER
• SESSION_USER
• SYSTEM_USER
• CURRENT SCHEMA
• CURRENT ISOLATION
• IDENTITY_VAL_LOCAL

This node is used rather than some use of MethodCallNode for runtime performance.

For a application call like CALL MYPROC(?) the logically Java method call is (in psuedo Java/SQL code) (examples with CHAR(10) parameter)
Fixed length IN parameters - com.acme.MyProcedureMethod(?)
Variable length IN parameters - com.acme.MyProcedureMethod(CAST (? AS CHAR(10))
Fixed length INOUT parameter - String[] holder = new String[] {?}; com.acme.MyProcedureMethod(holder); ? = holder[0]
Variable length INOUT parameter - String[] holder = new String[] {CAST (? AS CHAR(10)}; com.acme.MyProcedureMethod(holder); ? = CAST (holder[0] AS CHAR(10))
Fixed length OUT parameter - String[] holder = new String[1]; com.acme.MyProcedureMethod(holder); ? = holder[0]
Variable length INOUT parameter - String[] holder = new String[1]; com.acme.MyProcedureMethod(holder); ? = CAST (holder[0] AS CHAR(10))

For static method calls there is no pre-definition of an IN or INOUT parameter, so a call to CallableStatement.registerOutParameter() makes the parameter an INOUT parameter, provided: - the parameter is passed directly to the method call (no casts or expressions). - the method's parameter type is a Java array type. Since this is a dynmaic decision we compile in code to take both paths, based upon a boolean isINOUT which is dervied from the ParameterValueSet.