Difference between revisions of "SELECT"

From SQLZOO
Jump to: navigation, search
Line 11: Line 11:
 
<tr> <td align='right'>WARD</td> <td>SALESMAN</td><td>1250</td> </tr>
 
<tr> <td align='right'>WARD</td> <td>SALESMAN</td><td>1250</td> </tr>
 
<tr> <td align='right'>MARTIN</td> <td>SALESMAN</td><td>1250</td> </tr>
 
<tr> <td align='right'>MARTIN</td> <td>SALESMAN</td><td>1250</td> </tr>
<tr> <td align='right'>BLAKE</td> <td>MANAGER</td><td>2850</td> </tr>
 
<tr> <td align='right'>CLARK</td> <td>MANAGER</td><td>2450</td> </tr>
 
<tr> <td align='right'>SCOTT</td> <td>ANALYST</td><td>3000</td> </tr>
 
<tr> <td align='right'>KING</td> <td>PRESIDENT</td><td>5000</td> </tr>
 
 
</table>
 
</table>
 
<div class=qu>
 
<div class=qu>
Line 29: Line 25:
 
INSERT INTO EMP(ENAME,JOB, SAL) VALUES ('WARD',SALESMAN,1250);
 
INSERT INTO EMP(ENAME,JOB, SAL) VALUES ('WARD',SALESMAN,1250);
 
INSERT INTO EMP(ENAME,JOB, SAL) VALUES ('MARTIN',SALESMAN,1250);
 
INSERT INTO EMP(ENAME,JOB, SAL) VALUES ('MARTIN',SALESMAN,1250);
INSERT INTO EMP(ENAME,JOB, SAL) VALUES ('BLAKE',MANAGER,2850);
 
INSERT INTO EMP(ENAME,JOB, SAL) VALUES ('CLARK',MANAGER,2450);
 
INSERT INTO EMP(ENAME,JOB, SAL) VALUES ('SCOTT',ANALYST,3000);
 
INSERT INTO EMP(ENAME,JOB, SAL) VALUES ('KING',PRESIDENT,5000);
 
 
</div>
 
</div>
 
<div class=def>
 
<div class=def>

Revision as of 07:58, 3 January 2013

A SELECT statement gets data from a table. Each table contains rows and columns - you can SELECT some columns and ignore others

  • The column names on the select line control which columns you get
  • The FROM clause controls which table you access
schema:scott

The table EMP shows the year and the city hosting the Olympic Games.

EMP
ENAME JOB SAL
SMITH CLERK 800
ALLEN SALESMAN 1600
WARD SALESMAN1250
MARTIN SALESMAN1250

The SELECT statement returns results from a table. In this example the table is EMP and the columns are ENAME and JOB.

DROP TABLE EMP;

CREATE TABLE EMP(ENAME INT, JOB VARCHAR(20),SAL INT); INSERT INTO EMP(ENAME,JOB, SAL) VALUES ('SMITH','CLERK',800); INSERT INTO EMP(ENAME,JOB, SAL) VALUES ('ALLEN',SALESMAN,1600); INSERT INTO EMP(ENAME,JOB, SAL) VALUES ('WARD',SALESMAN,1250); INSERT INTO EMP(ENAME,JOB, SAL) VALUES ('MARTIN',SALESMAN,1250);

SELECT ENAME, JOB FROM games

See also:

Personal tools
Namespaces

Variants
Actions
Reference
Toolbox
Google AdSense