(mysql.info) key-column-usage-table

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(mysql.info) table-constraints-table

(mysql.info) information-schema

(mysql.info) routines-table

 
 20.13 The `INFORMATION_SCHEMA KEY_COLUMN_USAGE' Table
 =====================================================
 
 The `KEY_COLUMN_USAGE' table describes which key columns have
 constraints.
 
 *`INFORMATION_SCHEMA' 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'                       
 `REFERENCED_TABLE_SCHEMA'                            
 `REFERENCED_TABLE_NAME'                              
 `REFERENCED_COLUMN_NAME'                             
 
 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 has 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'.
 
    * `REFERENCED_TABLE_SCHEMA', `REFERENCED_TABLE_NAME', and
      `REFERENCED_COLUMN_NAME' were added in MySQL 5.0.6.
 

Info Catalog

(mysql.info) table-constraints-table

(mysql.info) information-schema

(mysql.info) routines-table