Thread by @Sukriti_Macker

SQL is the most wanted skill in Data Science!! 😱

A Beginner's Guide to MySQL basic queries - Part 3!! 😎

Making mistakes while creating tables is common. Let's learn how to update and fix them! 😬

Thread 🧵

✅ UPDATE THE TABLE

1. Add a column to the existing table:-

ALTER table table_name ADD (column_name datatype);

(Note: Adding a constraint to a column is optional)

👉 E.g., Adding the ADDRESS column to the classroom1 table.

2. Add MULTIPLE columns at once:-

ALTER table table_name ADD (colname1 datatype1, colname2 datatype2);

👉 E.g., Adding Email_id and ContactNo columns to the classroom1 table

3. Changing the name of a column:-

ALTER table table_name CHANGE old_column_name new_column_name datatype;

👉 E.g., Changing the column name rollno to ID

4. Modifying (Changing) the datatype of the existing column:-

ALTER table table_name MODIFY column_name datatype;

👉 E.g., Changing the datatype of the Address column to datatype CHAR.

5. Delete a column:-

ALTER table table_name DROP column column_name;

👉 E.g., Dropping the column EmailID from the classroom1 table.

6. Delete multiple columns at once:-

ALTER table table_name DROP column colname1, DROP column colname2;

👉 E.g., Dropping the columns ContactNo & Address from the classroom1 table.