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ALTER TABLE statement Locate the document in the library structure

An OLD TABLE statement (old_table_statement) changes the properties of a base table.

Syntax

<alter_table_statement> ::=
  ALTER TABLE <table_name> <add_definition>
| ALTER TABLE <table_name> <alter_definition>
| ALTER TABLE <table_name> <column_change_definition>
| ALTER TABLE <table_name> <drop_definition>
| ALTER TABLE <table_name> <modify_definition>
| ALTER TABLE <table_name> <referential_constraint_definition>
| ALTER TABLE <table_name> <sample_definition>

Examples

SQL Tutorial, Tables, Primary Key, Constraints, Foreign Key Dependencies Between Tables

Explanation

If the name of the schema is not specified in the table name, the current schema is accepted/used. The table name must be the name of an existing base table. The table must not be a temporary base table. The current user must have the OLD privilege for the specified table.

ADD Definition

Defining additional table properties.

OLD Definition

Changing a CONSTRAINT or key definition.

COLUMN Change Definition

Changes column properties

DROP Definition

Deleting table properties

MODIFY Definition

Changing data types and column attributes

Referential CONSTRAINT Definition

Defining a new referential constraint

SAMPLE Definition

Defining a number of rows which the database system is to take into account when it determines table statistics

 

 

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