General MySQL Oracle SQL Server

<< < … 8 9 10 11 12 13 14 15 16 17 > >>   ∑:386  Sort:Date

What Is a User Account in MySQL
What Is a User Account in MySQL? A user account is identified by a user name and defines the user's attributes, including the following: Password for connection authentication. User privileges, for examples: Shutdown_priv, Create_priv, Drop_priv, Insert_priv, Update_priv, Delete_priv, etc.. Various ... 2017-12-13, 2833🔥, 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&gt; SELECT tag, counts, url, DATE(created) FROM fyi_... 2017-11-02, 2825🔥, 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&gt; SELECT tag, ... 2017-11-02, 2823🔥, 0💬

Including Comments in SQL Statements in MySQL
How To Include Comments in SQL Statements in MySQL? If you want to include comments in a SQL statement, you can first enter "--", then enter your comment until the end of the line. The tutorial exercise below shows you some good examples: SELECT 'Hello world!' FROM DUAL; -- My first SQL statement! I... 2018-04-12, 2820🔥, 0💬

VALUES() - Column Value for "ON DUPLICATE KEY UPDATE"
How to obtain the inserting value of given column in the "ON DUPLICATE KEY UPDATE" clause using the VALUES() function? VALUES(col) is a MySQL built-in function that returns the inserting value of a given column and use it in the "ON DUPLICATE KEY UPDATE" clause. For example: CREATE TABLE MyTable (id... 2025-10-24, 2814🔥, 0💬

Converting Character Strings to Dates in MySQL
How To Convert Character Strings to Dates in MySQL? If you have a character string that represents a date, and you want to convert it into a date value, you can use the STR_TO_DATE(string, format) function. STR_TO_DATE() shares the same formatting codes with DATE_FORMAT() function. The tutorial exer... 2017-12-26, 2813🔥, 0💬

Filerting out Duplications in Returning Rows in MySQL
How To Filter Out Duplications in Returning Rows in MySQL? If there are duplications in the returning rows, and you want to remove the duplications, you can use the keyword DISTINCT in the SELECT clause. The DISTINCT applies to the combination of all data fields specified in the SELECT clause. The t... 2018-01-06, 2810🔥, 0💬

Entering Microseconds in SQL Statements in MySQL
How To Enter Microseconds in SQL Statements in MySQL? If you want to enter microseconds in a SQL statements, you can enter them right after the time string as a 6-digit number delimited with '.'. '0' will be padded to right if not enough digits. Here are some good examples: SELECT TIME('1997/01/31 0... 2017-12-26, 2809🔥, 0💬

Types of Table Joins in MySQL
How To Join Two Tables in a Single Query in MySQL? Two tables can be joined together in a query in 4 ways: Inner Join: Returns only rows from both tables that satisfy the join condition. Left Outer Join: Returns rows from both tables that satisfy the join condition, and the rest of rows from the fir... 2017-12-31, 2808🔥, 0💬

Server Daemon mysqld Administration in MySQL
Where to find answers to frequently asked questions on Server Daemon mysqld Administration in MySQL? Here is a list of frequently asked questions and their answers compiled by FYIcenter.com DBA team on Server Daemon mysqld Administration in MySQL. Clear answers are provided with tutorial exercises o... 2017-12-09, 2808🔥, 0💬

Drop an Existing Table in MySQL
How To Drop an Existing Table in MySQL? If you want to delete an existing table and its data rows, you can use the "DROP TABLE" statement as shown in the tutorial script below: mysql&gt; SELECT * FROM tipBackup; +----+-------------+---------- ---------------+-------------+| id | subject | descri... 2018-02-14, 2804🔥, 0💬

Assign Names to Query Output Columns in MySQL
How To Name Query Output Columns in MySQL? Each column in the query output has a default name. If you don't like the default name, you can specify a new name for any column in the query output by using the AS clause. The following statement shows you a good example: mysql&gt; SELECT tag AS Categ... 2017-09-28, 2803🔥, 0💬

What Is Foreign Key in MySQL
What Is Foreign Key in MySQL? A foreign key is a single column or multiple columns defined to have values that can be mapped to a primary key in another table.   ⇒ What Is Index in MySQL ⇐ What Is Primary key in MySQL ⇑ Database Basics and Terminologies in MySQL ⇑⇑ MySQL Database Tutorials 2017-07-07, 2798🔥, 0💬

CURRENT_ROLE() - Current Role of Logged-In User
How to obtain the current role of the logged-in user using the CURRENT_ROLE() function? CURRENT_ROLE() is a MySQL built-in function that returns the current role of the logged-in user. For example: SELECT CURRENT_ROLE(); -- +----------------+ -- | CURRENT_ROLE() | -- +----------------+ -- | NONE | -... 2024-07-15, 2796🔥, 0💬

CREATE TABLE Statement in MySQL
How To Create a New Table in MySQL? If you want to create a new table, you can use the "CREATE TABLE" statement. The following tutorial script shows you how to create a table called "tip": mysql&gt; CREATE TABLE tip (id INTEGER PRIMARY KEY, subject VARCHAR(80) NOT NULL, description VARCHAR(256) ... 2018-03-10, 2793🔥, 0💬

Retrieving MySQL Server information in MySQL
How To Get Some Basic Information Back from MySQL Servers in MySQL? Once you got a MySQL server connection object successfully, you can use mysql_get_server() and mysql_get_host_info() to get some basic information from your MySQL server. The tutorial exercise below is a good example: &lt;?php $... 2017-11-11, 2792🔥, 0💬

Start a New Transaction Explicitly in MySQL
How To Start a New Transaction Explicitly in MySQL? If you are confused on the implicit new transaction rules, you can always start a new transaction with the "START TRANSACTION" command to start a new transaction explicitly. "START TRANSACTION" command works in both "Autocommit On" and "Autocommit ... 2016-10-17, 2782🔥, 0💬

Giving User Read-only Access in MySQL
How To Give a User Read-Only Access to a Database in MySQL? If you want give a user read-only access to a database, you can grant to him/her only the "SELECT" privilege, so that he/she can not run any DDL statements, and any INSERT, UPDATE, or DELETE statements. The tutorial exercise gives you a goo... 2017-08-21, 2781🔥, 0💬

UNCOMPRESS() - Uncompressing Data
How to uncompress (restore) compressed data using the UNCOMPRESS() function? UNCOMPRESS(str) is a MySQL built-in function that uncompresses a given compressed byte string using the default LZ77 compression algorithm. For example: SELECT UNCOMPRESS(x'37000000789C738BF 44C4ECD2B492DD24BCECFD57123960 700... 2024-12-18, 2777🔥, 0💬

Data Removed in MEMORY Tables in MySQL
What Happens to MEMORY Tables When MySQL Server Is Stopped in MySQL? If you have data rows stored in a table with the MEMORY storage engine, and the MySQL server has been shut down by the DBA, all data rows will be removed. But the table structure will remain in the server. The tutorial exercise bel... 2017-08-08, 2777🔥, 0💬

Retrieving Execution Error Message in MySQL
How To Get MySQL Statement Execution Errors in MySQL? When you execute a MySQL statement with mysql_query(), and the statement failed, mysql_query() will return the Boolean value FALSE. This is good enough to tell that there is something wrong with that statement. But if you want to know more about ... 2017-10-23, 2771🔥, 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, 2770🔥, 0💬

Create a New View in MySQL
How To Create a New View in MySQL? You can create a new view based on one or more existing tables by using the "CREATE VIEW viewName AS selectStatement" statement as shown in the following script: mysql&gt; CREATE TABLE comment (faqID INTEGER, message VARCHAR(256)); Query OK, 0 rows affected (0.... 2018-01-24, 2765🔥, 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&gt; SELECT id, url FROM... 2017-11-05, 2762🔥, 0💬

<< < … 8 9 10 11 12 13 14 15 16 17 > >>   ∑:386  Sort:Date

General MySQL Oracle SQL Server