Deleting All Rows in a Table in MySQL

Q

How To Delete All Rows in a Table in MySQL?

✍: FYIcenter.com

A

If you want to delete all rows from a table, you have two options:

Use the DELETE statement with no WHERE clause.
Use the TRUNCATE TABLE statement.

The TRUNCATE statement is more efficient the DELETE statement. The tutorial exercise shows you a good example of TRUNCATE statement:

mysql> SELECT COUNT(*) FROM fyi_links;
+----------+
| COUNT(*) |
+----------+
|        5 |
+----------+
1 row in set (0.08 sec)

mysql> TRUNCATE TABLE fyi_links;
Query OK, 0 rows affected (0.02 sec)

mysql> SELECT COUNT(*) FROM fyi_links;
+----------+
| COUNT(*) |
+----------+
|        0 |
+----------+
1 row in set (0.00 sec)

⇒ SELECT Query Statements with GROUP BY in MySQL

⇐ Deleting Multiple Rows from a Table in MySQL

⇑ INSERT, UPDATE and DELETE Statements in MySQL

⇑⇑ MySQL Database Tutorials

2018-01-08, 2555🔥, 0💬

UPDATE with Subquery Returning No Rows in MySQL
What Happens If the UPDATE Subquery Returns No Rows in MySQL? If you use a subquery to assign new values in the SET clause in an UPDATE statement, and the subquery returns no rows for an outer row, MySQL will provide a NULL value to the SET clause. The tutorial exercise below shows you a good exampl... 2018-01-08, 3527🔥, 0💬

UPDATE Using Data from Other Tables in MySQL
How To Use Values from Other Tables in UPDATE Statements in MySQL? If you want to update values in one table with values from another table, you can use a subquery as an expression in the SET clause. The subquery should return only one row for each row in the update table that matches the WHERE clau... 2018-01-13, 3073🔥, 0💬

SELECT Query Statements with GROUP BY in MySQL
Where to find answers to frequently asked questions on SELECT Query Statements with GROUP BY in MySQL? Here is a list of frequently asked questions and their answers compiled by FYIcenter.com DBA team SELECT Query Statements with GROUP BY in MySQL. Clear answers are provided with tutorial exercises ... 2017-11-05, 2842🔥, 0💬

Create a Test Table with Test Data in MySQL
How To Create a Testing Table with Test Data in MySQL? If you want to follow the tutorial exercises presented in this collection, you need to create a testing table and insert some test data, as shown in the following sample script: mysql> CREATE TABLE fyi_links (id INTEGER PRIMARY KEY, url V... 2017-11-05, 2786🔥, 0💬

Deleting Multiple Rows from a Table in MySQL
How To Delete Multiple Rows from a Table in MySQL? You can delete multiple rows from a table in the same way as deleting a single row, except that the WHERE clause will match multiple rows. The tutorial exercise below deletes 3 rows from the fyi_links table: mysql> SELECT id, url, notes, coun... 2018-01-08, 2781🔥, 0💬

Deleting an Existing Row from a Table in MySQL
How To Delete an Existing Row from a Table in MySQL? If you want to delete an existing row from a table, you can use the DELETE statement with a WHERE clause to identify that row. Here is good sample of DELETE statements: mysql> INSERT INTO fyi_links (url, id) VALUES ('www.myspace.com', 301);... 2018-01-08, 2607🔥, 0💬

Deleting All Rows in a Table in MySQL
How To Delete All Rows in a Table in MySQL? If you want to delete all rows from a table, you have two options: Use the DELETE statement with no WHERE clause. Use the TRUNCATE TABLE statement. The TRUNCATE statement is more efficient the DELETE statement. The tutorial exercise shows you a good exampl... 2018-01-08, 2556🔥, 0💬

Selecting All Columns of All Rows in MySQL
How To Select All Columns of All Rows from a Table in MySQL? The simplest query statement is the one that selects all columns of all rows from a single table: "SELECT * FROM tableName;". The (*) in the SELECT clause tells the query to return all columns. The missing WHERE clause tells the query to r... 2017-11-05, 2417🔥, 0💬

Selecting Columns in a Query in MySQL
How To Select Some Columns from a Table in MySQL? If you want explicitly tell the query to return some columns, you can specify the column names in the SELECT clause. The following select statement returns only two columns, "id" and "url" from the table "fyi_links": mysql> SELECT id, url FROM... 2017-11-05, 2284🔥, 0💬

All rights in the contents of this web site are reserved by the individual author. fyicenter.com does not guarantee the truthfulness, accuracy, or reliability of any contents.