Write a SQL statement to drop the index indx_job_id from job_history table.ĭo not submit any solution of the above exercises at here, if you want to contribute go to the appropriate exercise page. Write a SQL statement to add an index named indx_job_id on job_id column in the table job_history.ġ5. Keep in mind that you cannot rename a column to a name that already exists in the table. Write a SQL statement to drop the existing foreign key fk_job_id from job_history table on job_id column which is referencing to the job_id of jobs table.ġ4. To change a column name, enter the following statement in your MySQL shell: ALTER TABLE tablename RENAME COLUMN oldcolumnname TO newcolumnname Replace tablename, oldcolumnname, and newcolumnname with your table and column names. Write a SQL statement to add a foreign key constraint named fk_job_id on job_id column of job_history table referencing to the primary key job_id of jobs table.ġ3. Write a SQL statement to add a foreign key on job_id column of job_history table referencing to the primary key job_id of jobs table.ġ2. Write a SQL statement to drop the existing primary from the table locations on a combination of columns location_id and country_id.ġ1. Write a SQL statement to add a primary key for a combination of columns location_id and country_id.ġ0. Write a SQL statement to add a primary key for the columns location_id in the locations table.ĩ. Write a SQL statement to change the name of the column state_province to state, keeping the data type and size same.Ĩ. Write a SQL statement to drop the column city from the table locations.ħ. Write a SQL statement change the data type of the column country_id to integer in the table locations.Ħ. Write a SQL statement to add a column region_id after state_province to the table locations.ĥ. Write a SQL statement to add a columns ID as the first column of the table locations.Ĥ. Write a SQL statement to add a column region_id to the table locations.ģ. Write a SQL statement to rename the table countries to country_new.Ģ. Note: on Checking its index is also updated to a new column name i.e officecode_new.MySQL Alter Table ġ. Officecode_new|varchar(200)|YES |MUL| | |

+-+-+-+-+-+Ĭhange the column office code to officecode_new and modify its datatype also with varchar(100).Īlter table employees change column officecode officecode_new varchar(200) ĭescribe the employee table again and check the index on the table on the column is also modified with a new name Field |Type |Null|Key|Default|Extra| Syntax: ALTER TABLE table_name CHANGE COLUMN old_col_name new_col_name column_definition Use the CHANGE clause to rename the column and If a column has an index, then it’s also updated. Rename the column name done with ALTER command with the CHANGE clause. Rename the column name in MySQL / MariaDB

Mysql rename column