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Number of Rows Selected or Affected in MySQL
How To Get the Number of Rows Selected or Affected by a SQL Statement in MySQL? There are two functions you can use the get the number of rows selected or affected by a SQL statement: mysql_num_rows($res) - Returns the number of rows selected in a result set object returned from SELECT statement. my...
2017-10-08, 342👍, 0💬

"CREATE LOGIN" - Creating a New Login Name in SQL Server
How To Create a New Login Name in SQL Server in SQL Server? In previous tutorials, it is assumed that you use the "sa" (System Administrator) login name to connect to your SQL Server. But that is not what a normal developer uses to connect to the server, since "sa" has the ALL permissions granted. Y...
2016-10-20, 342👍, 0💬

What Is NULL Value in MySQL
What Are NULL Values in MySQL? NULL is a special value that represents no value. Here are basic rules about NULL values: NULL presents no value. NULL is not the same as an empty string ''. NULL is not the same as a zero value 0. NULL can be used as any data type. NULL should not be used in any compa...
2018-03-28, 341👍, 0💬

Merge Outputs from Two Queries in MySQL
How To Use UNION to Merge Outputs from Two Queries Together in MySQL? If you have two queries that returns the same row fields, you can merge their outputs together with the UNION operator. The following tutorial exercise shows you how to return all links that were created since year 2006 plus the o...
2017-12-21, 341👍, 0💬

Query with a Right Outer Join in MySQL
How To Write a Query with a Right Outer Join in MySQL? If you want to query from two tables with a right outer join, you can use the RIGHT OUTER JOIN ... ON clause in the FROM clause. The following query returns output with a right outer join from two tables: fyi_links and fyi_rates. The join condit...
2017-09-28, 341👍, 0💬

"RETURNS TABLE" - Creating Inline Table-Value Functions in SQL Server
How To Create an Inline Table-Valued Function in SQL Server Transact-SQL? To create an inline table-valued function, you need to use the "RETURNS TABLE" clause in the "CREATE FUNCTION" statement. There should be no function body, except for a RETURN statement with a SELECT subquery: An inline table-...
2016-12-18, 341👍, 0💬

What Is a Database in SQL Server
What is a database in SQL Server? A database is a logical container that contains a set of related database objects: Tables - Storages of structured data. Views - Queries to present data from tables. Indexes - Sorting indexes to speed up searches. Stored Procedures - Predefined SQL program units. Us...
2016-11-24, 341👍, 0💬

Deleting All Rows with TRUNCATE TABLE Statement in SQL Server
How To Delete All Rows with TRUNCATE TABLE Statement in SQL Server? 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...
2016-10-30, 341👍, 0💬

Creating and Managing Triggers in SQL Server
Where to find answers to frequently asked questions on Creating and Managing Triggers in SQL Server? Here is a list of frequently asked questions and their answers compiled by FYIcenter.com DBA team on Creating and Managing Triggers in SQL Server. Clear explanations and tutorial exercises are provid...
2016-10-25, 341👍, 0💬

Suser_Sname() - Sever Level Security Principal of Your Session in SQL Server
What Is the Security Principal at the Server Level That Represents Your Session in SQL Server? Security principal identifies who you are when you interact with the SQL Server. What can do you at the server level solely depends on the security principal that represents you. So it is very important to...
2016-10-20, 341👍, 0💬

"ALTER LOGIN" - Changing the Password of a Login Name in SQL Server
How To Change the Password of a Login Name in SQL Server? If a developer lost the password of his or her login name, you can reset the password with the "ALTER LOGIN" statement as shown in this tutorial example: -- Login with sa ALTER LOGIN FYI_DBA WITH PASSWORD = 'fyicenter'; GO Command(s) complete...
2016-10-20, 341👍, 0💬

Joining Two Tables in a Single Query in SQL Server
How To Join Two Tables in a Single Query in SQL Server? 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 th...
2016-10-30, 340👍, 0💬

Modes of Data Dump Export and Import in Oracle
What Are Data Pump Export and Import Modes in Oracle? Data Pump export and import modes are used to determine the type and portions of database to be exported and imported. Oracle 10g supports 5 export and import modes: Full: Exports and imports a full database. Use the FULL parameter to specify thi...
2016-10-15, 340👍, 0💬

Defragmenting Table Indexes in SQL Server
How To Defragment Table Indexes in SQL Server? When a table index is fragmented to a certain percentage, you need to defragment the index to maintain its performance level. There are 3 ways to defragment: 1. "ALTER INDEX index_name ON table_name REORGANIZE" - Defragmenting the specified index perfor...
2016-11-08, 339👍, 0💬

Sorting Query Output with ORDER BY Clauses in SQL Server
How To Sort the Query Output with ORDER BY Clauses in SQL Server? 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 b...
2016-10-26, 339👍, 0💬

Rollback the Current Transaction in MySQL
How To Rollback the Current Transaction in MySQL? If you have used some DML statements updated some data objects, you find a problem with those updates, and you don't want those updates to be permanently recorded in the database, you can use the ROLLBACK command. It will remove all the database chan...
2016-10-17, 339👍, 0💬

What Is a Procedure in Oracle
What Is a Procedure in Oracle? A procedure is a named program unit. It consists of three parts: Declaration Part - Defining the procedure name, calling parameters, local variables and local procedures. Declaration part is required. Execution Part - Defining execution logic with executable statements...
2018-01-27, 338👍, 0💬

What Are Group Functions in MySQL
What Are Group Functions in MySQL? Group functions are functions applied to a group of rows. Examples of group functions are: COUNT(*) - Returns the number of rows in the group. MIN(exp) - Returns the minimum value of the expression evaluated on each row of the group. MAX(exp) - Returns the maximum ...
2018-01-06, 338👍, 0💬

Connect to MySQL Server with Port Number in MySQL
How To Connect to a MySQL Server with a Port Number in MySQL? If you want to connect a MySQL server with a non-default port number, you need to use the "mysql_connect($server)" function with $server in the format of "hostName:portNubmber". The tutorial exercise below shows you how to connect to loca...
2017-11-25, 338👍, 0💬

Renaming Database Names in SQL Server
How to rename databases in SQL Server? If don't like the name of a database, you can change it by using the "ALTER DATABASE" statement with the following syntax: ALTER DATABASE database_name MODIFY NAME = new_database_name The tutorial example below shows you how change the database name from "FyiCe...
2016-11-24, 338👍, 0💬

"AS" - Naming Query Output Columns in SQL Server
How To Name Query Output Columns in SQL Server? 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: SELECT tag AS Category, YEAR...
2016-10-29, 338👍, 0💬

Rolling Back the DDL Statement in a Trigger in SQL Server
Can You Roll Back the DDL Statement in a Trigger in SQL Server? Can you roll back the DDL statement in a trigger? The answer is yes. Since the DDL statement that fires the trigger and the statements defined inside the trigger are all executed as a single statement batch, you can add a ROLLBACK state...
2016-10-22, 338👍, 0💬

Verifying a Login Name with SQLCMD Tool in SQL Server
How To Verify a Login name with SQLCMD Tool in SQL Server? The quickest way to verify a login name on a SQL Server is probably to use the SQLCMD tool, which takes the server name, login name and password in a single command line. Here is how to try it yourself: Start a command window and enter the f...
2016-10-20, 338👍, 0💬

Character String Data Types in MySQL
What Are Character String Data Types in MySQL? MySQL supports the following string data types: CHAR(n) same as CHARACTER(n) - Fixed width and " " padded characters strings. Default character set is ASCII. NCHAR(n) same as NATIONAL CHARACTER(n) - Fixed width and " " padded character strings with UTF8...
2018-04-12, 337👍, 0💬

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