Using a Join to Create a Lookup Table from Descriptive Labels : Simple JOIN « Join « SQL / MySQL





Using a Join to Create a Lookup Table from Descriptive Labels

     
mysql>
mysql> CREATE TABLE coin
    -> (
    ->     id INT UNSIGNED NOT NULL AUTO_INCREMENT,
    ->     date CHAR(5) NOT NULL, # 4 digits + mint letter
    ->     denom CHAR(20) NOT NULL, # denomination (e.g., Lincoln cent)
    ->     PRIMARY KEY (id)
    -> );
Query OK, 0 rows affected (0.00 sec)

mysql>
mysql> CREATE TABLE denom
    -> (
    ->  denom_id        INT UNSIGNED NOT NULL AUTO_INCREMENT,
    ->  PRIMARY KEY (denom_id)
    -> )
    -> SELECT DISTINCT denom AS name FROM coin;
Query OK, 0 rows affected (0.01 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql>
mysql>
mysql> INSERT INTO coin (date,denom) VALUES('1944s','Lincoln cent');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO coin (date,denom) VALUES('1977','Roosevelt dime');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO coin (date,denom) VALUES('1955d','Lincoln cent');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO coin (date,denom) VALUES('1938','Jefferson nickel');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO coin (date,denom) VALUES('1964','Kennedy half dollar');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO coin (date,denom) VALUES('1959','Lincoln cent');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO coin (date,denom) VALUES('1945','Jefferson nickel');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO coin (date,denom) VALUES('1905','Buffalo nickel');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO coin (date,denom) VALUES('1924','Mercury head dime');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO coin (date,denom) VALUES('2010','Roosevelt dime');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO coin (date,denom) VALUES('1937','Mercury head dime');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO coin (date,denom) VALUES('1977','Kennedy half dollar');
Query OK, 1 row affected (0.00 sec)

mysql>
mysql> INSERT INTO denom (name) SELECT DISTINCT denom FROM coin;
Query OK, 6 rows affected (0.00 sec)
Records: 6  Duplicates: 0  Warnings: 0

mysql>
mysql> drop table denom;
Query OK, 0 rows affected (0.00 sec)

mysql> drop table coin;
Query OK, 0 rows affected (0.00 sec)

   
    
    
    
    
  










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