MYSQL UPDATE STATEMENT UPDATE
Here is an example updating Manager of all records: UPDATE Person JOIN table_name2 ON table_name1.ForeignKey = table_name2.Key Use JOIN clause to get data from multiple tables. You can also update columns in a table by using values from other tables. Here is an example updating the Name of the record with Id 4: UPDATE Person It is possible to update one or more columns at a time. Use the WHERE condition to specify which records do you want to update. You can update all records of the table or just a few. To update a record in a table you use the UPDATE statement.īe careful.
MYSQL UPDATE STATEMENT MANUAL
Please see the manual for your database manager and have fun trying different options yourself. I hope this at least gives you enough to get started. Boyce | 2400 | Computer Science | |Īs with all of these SQL things there is MUCH MORE to them than what’s in this introductory guide. | Edgar Frank "Ted" Codd | 2400 | Computer Science | | | Sophie Freeman | 1200 | Programming | | | Spencer Pautier | 1000 | Programming | | Success! mysql> SELECT FullName, sat_score, programOfStudy, schoolEmailAdr FROM student We’ll pretend that this is what we want and update the table with this information: UPDATE student SET schoolEmailAdr = concat(substring(FullName,1,instr(FullName," schoolEmailAdr is NULL In this usage it works like this: The substring of the FullName field up to but not including the first space is combined with In the real world this would HAVE TO be much more complex and you would need to ensure that the email address is unique. | FullName | firstSpacePosition | schoolEmail |Ī note about concat(): in MySQL this command is used to combined strings, not so in other SQL versions (check your manual). TESTING the logic (VERY important step!) SELECT FullName, instr(FullName," ") AS firstSpacePosition,Ĭoncat(substring(FullName,1,instr(FullName," AS schoolEmail
Chamberlin | 2400 | Computer Science | NULL |
| Edgar Frank "Ted" Codd | 2400 | Computer Science | NULL | | Sophie Freeman | 1200 | Programming | NULL | | Alvin Greene | 1200 | Programming | NULL | | Louis Ramsey | 1200 | Programming | NULL | | Spencer Pautier | 1000 | Programming | NULL | | Teri Gutierrez | 800 | Programming | NULL | | Monique Davis | 400 | Literature | NULL | | FullName | sat_score | programOfStudy | schoolEmailAdr | mysql> SELECT FullName, sat_score, programOfStudy, schoolEmailAdr FROM student The student table after the alter is executed. Boyce | 2400 | Computer Science | 15:35:33 | 15:35:33 |Īlter the table and add a new field ALTER TABLE `fcc_sql_guides_database`.`student`ĪDD COLUMN `schoolEmailAdr` VARCHAR(125) NULL AFTER `programOfStudy` | studentID | FullName | sat_score | programOfStudy | rcd_Created | rcd_Updated | Here is the student table as we start this process SELECT * FROM student test the logic to update that field with a school assigned email address.
Important Safety Tip: always have a backup copy of what you are about to change BEFORE you change it. An update query gives the DBA or SQL-using programmer the ability to update many records with one command.
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