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SQL programmingYou can use the HCL OneDB™ implementation of the SQL language to develop applications for HCL OneDB™ database servers.
Guide to SQL: SyntaxThe HCL OneDB™ Guide to SQL: Syntax describes the syntax of the statements, data types, expressions, operators, and built-in functions of the HCL OneDB™ dialect of the SQL language.
SQL statementsThis chapter describes the syntax and semantics of SQL statements that are recognized by HCL OneDB™.
ALTER TABLE statementUse the ALTER TABLE statement to modify the schema of an existing table.
ADD Column ClauseUse the ADD Column clause to add a column to a table, and to define constraints on the new column. This clause can also associate a security policy with a table that has no security policy, or can specify a security label for the new column, if the table already has a security policy.
BEFORE ClauseThe optional BEFORE clause determines the ordinal positions of the new columns within the schema of the table by specifying the name of an existing column before which the ALTER TABLE ADD statement inserts the new columns.

BEFORE Clause

The optional BEFORE clause determines the ordinal positions of the new columns within the schema of the table by specifying the name of an existing column before which the ALTER TABLE ADD statement inserts the new columns.

About this task

In the following example, the BEFORE option directs the database server to add the item_weight column before the total_price column:

ALTER TABLE items
   ADD (item_weight DECIMAL(6,2) NOT NULL BEFORE total_price);

By default, if you do not include the BEFORE clause, the database server appends the new columns after the last column in the current schema of the table, in their lexical order within the ADD clause.

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