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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 CONSTRAINT ClauseUse the ADD CONSTRAINT clause to specify a primary key, foreign key, referential, unique, or check constraint on a new or existing column or on a set of columns.
Multiple-Column Constraint FormatUse this option to assign one or more constraints to a column or to a set of columns in an existing table.
Recovery from Constraint Violations

Recovery from Constraint Violations

If you use the ADD CONSTRAINT clause to add a constraint in the enabled mode, you receive an error message because existing rows would violate the constraint. For a procedure to add the constraint successfully, see Adding a Constraint That Existing Rows Violate.