The Teradata UPDATE statement is used to update records in an existing Teradata table. Update of records can be done on one or more Teradata columns using a single UPDATE statement.
Teradata UPDATE Statement syntax
The generic syntax for updating all the columns in a table is as below.
UPDATE database_name.table_name SET column_name = value;
For updating specific records WHERE
condition needs to be added as follows.
UPDATE database_name.table_name SET column_name = value WHERE condition;
You can update multiple columns in a single update statement as well. The syntax for doing the same as below.
UPDATE database_name.table_name SET column1 = value1, column2 = value2, ... columnN = valueN WHERE condition;
Parameters Explanation
Parameter | Explanation |
database_name | The name of the owner database for the table. |
table_name | The name of the table from where you want to delete all the records. |
where condition | The condition for deleting specific row(s). |
column_name | The name of the column which you want to update. |
value | The new value needs to be updated. |
Teradata UPDATE Statement example
Consider the following Employee
table.
1) Updating Specific Records
The below statement updates the designation TRAINEE to BUSINESS ANALYST.
UPDATE TUTORIALSBOOK.Employee SET DESIGNATION='BUSINESS ANALYST' WHERE DESIGNATION='TRAINEE'; *** Update completed. One row changed. *** Total elapsed time was 1 second.
We can verify the update rows in the Employee table using the select statement.
2) Updating Multiple Columns
The following statement updates multiple columns in a single statement.
UPDATE TUTORIALSBOOK.Employee SET DESIGNATION='ASSISTANT MANAGER', SALARY=50000 WHERE DESIGNATION='BUSINESS ANALYST'; *** Update completed. 2 rows changed. *** Total elapsed time was 1 second.
Let’s check the Employee table to check the changes.
*** Query completed. 8 rows found. 7 columns returned. *** Total elapsed time was 1 second. EMPNO FIRST_NAME LAST_NAME HIREDATE DESIGNATION SALARY DEPTNO ----------- ------------------------- ------------------------- ---------- -------------------- ---------- ----------- 1001 STEFAN SALVATORE 2001-04-12 ASSISTANT MANAGER 50000.00 40 1002 DIANA LORANCE 2005-01-05 TECHNICAL ARCHITECT 75000.00 10 1003 JAMES MADISON 2005-09-18 MANAGER 60000.00 20 1004 JONES NICK 2004-08-19 HR ANALYST 35000.00 30 1005 LUCY GILLER 2006-04-01 HR ASSOCIATE 30000.00 30 1006 ISSAC STEFAN 2002-11-18 ASSISTANT MANAGER 50000.00 10 1007 NANCY GILBERT 2003-04-06 CLERK 18000.00 10 1008 JOHN SMITH 2005-10-12 SALESMAN 20000.00 10
3) Updating all records in a column
The below statement updates all the records of the DEPTNO
column to 50
.
UPDATE TUTORIALSBOOK.Employee SET DEPTNO=50; *** Update completed. 8 rows changed. *** Total elapsed time was 1 second.
Finally check the Employee table to see the changes.
*** Query completed. 8 rows found. 7 columns returned. *** Total elapsed time was 1 second. EMPNO FIRST_NAME LAST_NAME HIREDATE DESIGNATION SALARY DEPTNO ----------- ------------------------- ------------------------- ---------- -------------------- ---------- ----------- 1001 STEFAN SALVATORE 2001-04-12 ASSISTANT MANAGER 50000.00 50 1002 DIANA LORANCE 2005-01-05 TECHNICAL ARCHITECT 75000.00 50 1003 JAMES MADISON 2005-09-18 MANAGER 60000.00 50 1004 JONES NICK 2004-08-19 HR ANALYST 35000.00 50 1005 LUCY GILLER 2006-04-01 HR ASSOCIATE 30000.00 50 1006 ISSAC STEFAN 2002-11-18 ASSISTANT MANAGER 50000.00 50 1007 NANCY GILBERT 2003-04-06 CLERK 18000.00 50 1008 JOHN SMITH 2005-10-12 SALESMAN 20000.00 50