YouTip

# SQLite Alter Command SQLite's **ALTER TABLE** command does not modify an existing table by performing a complete dump and reload of data. You can use the ALTER TABLE statement to rename a table, and you can also use the ALTER TABLE statement to add additional columns to an existing table. In SQLite, apart from renaming a table and adding columns to an existing table, the ALTER TABLE command does not support other operations. ## Syntax The basic syntax for renaming an existing table using **ALTER TABLE** is as follows: ALTER TABLE database_name.table_name RENAME TO new_table_name; The basic syntax for adding a new column to an existing table using **ALTER TABLE** is as follows: ALTER TABLE database_name.table_name ADD COLUMN column_def...; ## Example Assume our COMPANY table has the following records: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ----------1 Paul 32 California 20000.02 Allen 25 Texas 15000.03 Teddy 23 Norway 20000.04 Mark 25 Rich-Mond 65000.05 David 27 Texas 85000.06 Kim 22 South-Hall 45000.07 James 24 Houston 10000.0 Now, let us try to rename the table using ALTER TABLE statement as follows: sqlite> ALTER TABLE COMPANY RENAME TO OLD_COMPANY; The above SQLite statement will rename the COMPANY table to OLD_COMPANY. Now, let us try to add a new column to the OLD_COMPANY table as follows: sqlite> ALTER TABLE OLD_COMPANY ADD COLUMN SEX char(1); Now, the COMPANY table has been changed, and the SELECT statement would display the following output: ID NAME AGE ADDRESS SALARY SEX ---------- ---------- ---------- ---------- ---------- ---1 Paul 32 California 20000.02 Allen 25 Texas 15000.03 Teddy 23 Norway 20000.04 Mark 25 Rich-Mond 65000.05 David 27 Texas 85000.06 Kim 22 South-Hall 45000.07 James 24 Houston 10000.0 Please note that the newly added column is filled with NULL values.