(mysql.info.gz) KEY_COLUMN_USAGE Table

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(mysql.info.gz) TABLE_CONSTRAINTS Table

(mysql.info.gz) INFORMATION_SCHEMA Tables

(mysql.info.gz) ROUTINES Table

 
 21.1.13 The `INFORMATION_SCHEMA KEY_COLUMN_USAGE' Table
 -------------------------------------------------------
 
 The `KEY_COLUMN_USAGE' table describes which key columns have
 constraints.
 
 *Standard Name*               *`SHOW' name*          *Remarks*
 `CONSTRAINT_CATALOG'                                 `NULL'
 `CONSTRAINT_SCHEMA'                                  
 `CONSTRAINT_NAME'                                    
 `TABLE_CATALOG'                                      
 `TABLE_SCHEMA'                                       
 `TABLE_NAME'                                         
 `COLUMN_NAME'                                        
 `ORDINAL_POSITION'                                   
 `POSITION_IN_UNIQUE_CONSTRAINT'                       
 
 Notes:
 
    * If the constraint is a foreign key, then this is the column of the
      foreign key, not the column that the foreign key references.
 
    * The value of `ORDINAL_POSITION' is the column's position within
      the constraint, not the column's position within the table.
      Column positions are numbered beginning with 1.
 
    * The value of `POSITION_IN_UNIQUE_CONSTRAINT' is `NULL' for unique
      and primary-key constraints. For foreign-key constraints, it is
      the ordinal position in key of the table that is being referenced.
 
      For example, suppose that there are two tables name `t1' and `t3'
      that have the following definitions:
 
           CREATE TABLE t1
           (
               s1 INT,
               s2 INT,
               s3 INT,
               PRIMARY KEY(s3)
           ) ENGINE=InnoDB;
 
           CREATE TABLE t3
           (
               s1 INT,
               s2 INT,
               s3 INT,
               KEY(s1),
               CONSTRAINT CO FOREIGN KEY (s2) REFERENCES t1(s3)
           ) ENGINE=InnoDB;
 
      For those two tables, the `KEY_COLUMN_USAGE' table will have two
      rows:
 
         * One row with `CONSTRAINT_NAME'='PRIMARY', `TABLE_NAME'='t1',
           `COLUMN_NAME'='s3', `ORDINAL_POSITION'=1,
           `POSITION_IN_UNIQUE_CONSTRAINT'=NULL.
 
         * One row with `CONSTRAINT_NAME'='CO', `TABLE_NAME'='t3',
           `COLUMN_NAME'='s2', `ORDINAL_POSITION'=1,
           `POSITION_IN_UNIQUE_CONSTRAINT'=1.
 
 
 

Info Catalog

(mysql.info.gz) TABLE_CONSTRAINTS Table

(mysql.info.gz) INFORMATION_SCHEMA Tables

(mysql.info.gz) ROUTINES Table