JDBC Driver for SQL/MX Programmer's Reference

<clobTableName> | <blobTableName> is:

<table_name> is:

[<catalogName>.][<schemaName>.]<baseTableName>

<baseTableName> is the table that contains LOB column(s).

<lobTableName> is the table that contains the LOB data.

Using SQL/MX Triggers to Delete LOB Data

Use the JDBC/MX Lob Admin Utility to generate triggers to delete LOB data from the LOB table when the base

row is deleted. These triggers ensure that orphan LOB data does not occur in the LOB table. To manage the

triggers, use these JDBC/MX Lob Admin Utility options:

-trigger

Generates SQL statements to create triggers.

-drop

Generates SQL statements drop triggers.

For example, the following command (typed on one line) generates the SQL statements to create the triggers for

the base table sales.paris.pictures, which contains a BLOB column, and executes those statements.

java -Djdbcmx.blobTableName=sales.paris.lobTable4pictures JdbcMxLobAdmin

-trigger

-exec sales.paris.pictures

Limitations of the CLOB and BLOB Data

Types

Limitations of the CLOB and BLOB data types, collectively referred to as LOB data, are:

LOB columns can only be in the target column list of these SQL statements:

INSERT statement,❍

Select list of a SELECT statement❍

Column name in the SET clause of an UPDATE statement❍

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LOB columns cannot be referenced in the SQL/MX functions and expressions.●

LOB data is not deleted from the LOB table when the base row is deleted unless a trigger is established. For

information about triggers, see Using an SQL/MX Trigger to Delete LOB Data.

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LOB data is not accessible if the base table name is changed.●

LOB columns cannot be copied to another table by using the SQL/MX utility commands.●

The name of a base table that has CLOB or BLOB columns must be unique across all catalogs and schemas

when more than one of these base tables share a single LOB table.

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