Selecting Columns in a Query in MySQL

Q

How To Select Some Columns from a Table in MySQL?

✍: FYIcenter.com

A

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 fyi_links;
+-----+-------------------+
| id  | url               |
+-----+-------------------+
| 101 | dev.fyicenter.com |
| 102 | dba.fyicenter.com |
| 103 | sqa.fyicenter.com |
+-----+-------------------+
3 rows in set (0.00 sec)

⇒ Select Rows with WHERE Clause in MySQL

⇐ Selecting All Columns of All Rows in MySQL

⇑ SELECT Query Statements with GROUP BY in MySQL

⇑⇑ MySQL Database Tutorials

2017-11-05, 2380🔥, 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, 2886🔥, 0💬

Select Rows with WHERE Clause in MySQL
How To Select Some Rows from a Table in MySQL? If you don't want select all rows from a table, you can specify a WHERE clause to tell the query to return only the rows that meets the condition defined in the WHERE clause. The WHERE clause condition is a normal Boolean expression. If any data from ta... 2017-11-02, 2776🔥, 0💬

Sorting Query Output in MySQL
How To Sort the Query Output in MySQL? If you want the returning rows to be sorted, you can specify a sorting expression in the ORDER BY clause. The simplest sort expression is column name who's values will be sorted by. The following select statement returns rows sorted by the values in the "counts... 2017-11-02, 2713🔥, 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, 2687🔥, 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, 2563🔥, 0💬

Sorting Output in Descending Order in MySQL
How To Sort Output in Descending Order in MySQL? If you want to sort a column in descending order, you can specify the DESC keyword in the ORDER BY clause. The following SELECT statement first sorts the "tag" in descending order, then sorts the "counts" in ascending order: mysql> SELECT tag, ... 2017-11-02, 2492🔥, 0💬

Sort by Multiple Columns in MySQL
Can the Query Output Be Sorted by Multiple Columns in MySQL? You can specifying multiple columns in the ORDER BY clause as shown in the following example statement, which returns employees' salaries sorted by department and salary value: mysql> SELECT tag, counts, url, DATE(created) FROM fyi_... 2017-11-02, 2459🔥, 0💬

Adding More Data to the Test Table in MySQL
How To Add More Data to the Testing Table in MySQL? If you want to continue with other tutorial exercises in this FAQ collection, you need to add more data to the testing table. Follow the script below to add a new column and: mysql> ALTER TABLE fyi_links ADD COLUMN tag VARCHAR(8); mysql&... 2017-11-02, 2387🔥, 0💬

What Is a SELECT Query Statement in MySQL
What Is a SELECT Query Statement in MySQL? The SELECT statement is also called the query statement. It is the most frequently used SQL statement in any database application. A SELECT statement allows you to retrieve data from one or more tables or views, with different selection criteria, grouping c... 2017-11-05, 2383🔥, 0💬

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