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Using User Defined Functions in Expressions in SQL Server
How To Use User Defined Functions in Expressions in SQL Server Transact-SQL? An user defined function must return a value, which can be used in any expression as long as the return value data type matches the expression. To execute a user defined function and use its return value in an expression, y...
2016-12-24, 273👍, 0💬

"DROP SCHEMA" - Dropping an Existing Schema in SQL Server
How To Drop an Existing Schema in SQL Server? If you want to delete a schema, you need to move all objects out of that schema, then use the "DROP SCHEMA" statement to delete the schema. The tutorial exercise below shows you how to drop schema "fyi": -- Login with "sa" USE FyiCenterData; GO -- Drop f...
2016-10-20, 273👍, 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, 272👍, 0💬

Using Group Functions in the ORDER BY Clause in MySQL
Can Group Functions Be Used in the ORDER BY Clause in MySQL? If the query output is aggregated as groups, you can sort the groups by using group functions in the ORDER BY clause. The following statement returns how many links were created in each year in each tag. The group output is sorted by the c...
2017-12-31, 272👍, 0💬

Using Subqueries with the IN Operators in SQL Server
How To Use Subqueries with the IN Operators in SQL Server? A subquery can be used with the IN operator as "expression IN (subquery)". The subquery should return a single column with one or more rows to form a list of values to be used by the IN operation. The following tutorial exercise shows you ho...
2016-10-29, 272👍, 0💬

Testing DML Triggers in SQL Server
How To Test a DML Trigger in SQL Server? To test a DML trigger defined on a table, you just need to execute several INSERT, UPDATE and DELETE statements on that table as shown in this tutorial example: USE FyiCenterData; GO INSERT INTO fyi_users (name) VALUES ('FYI Admin'); GO Records are inserted, ...
2016-10-25, 272👍, 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, 272👍, 0💬

Ways to Start MySQL Server in MySQL
How To Start MySQL Server Daemon mysqld in MySQL? There are a number of ways to start MySQL server daemon, mysqld: Double click on the file name, mysqld.exe, in a file explorer window. This is an easy way to start the server. But you will not be able to specify any command line options. Enter "mysql...
2017-12-04, 271👍, 0💬

Using Old Values to Define New Values in UPDATE Statements in SQL Server
How to use old values to define new values in UPDATE statements in SQL Server? If a row matches the WHERE clause in a UPDATE statement, existing values in this row can be used in expressions to provide new values in the SET clause. Existing values are represented by column names in the expressions. ...
2016-11-02, 271👍, 0💬

Writing Inner Joins with the WHERE Clause in SQL Server
How To Write an Inner Join with the WHERE Clause in SQL Server? If you don't want to use the INNER JOIN ... ON clause to write an inner join, you can put the join condition in the WHERE clause as shown in the following query example: SELECT l.id, l.url, r.comment FROM fyi_links l, fyi_rates r WHERE ...
2016-10-29, 271👍, 0💬

"INSERTED" - New Record of an DML Event Instance in SQL Server
How To Access the Inserted Record of an Event in SQL Server? When a DML event occurs, SQL Server will prepare a temporary table called "INSERTED", which contains the new record of the affected row, which is: A copy of the inserted row for an INSERT statement. A copy of the updated row for an UPDATE ...
2016-10-24, 271👍, 0💬

"DROP TRIGGER" - Deleting Existing Triggers in SQL Server
How To Delete Existing Triggers using "DROP TRIGGER" in SQL Server? If you don't want to use a trigger any more, you should delete it from the database by using the "DROP TRIGGER" statement as shown in tutorial example: USE FyiCenterData; GO DROP TRIGGER new_user; GO SELECT * FROM sys.triggers GO na...
2016-10-24, 271👍, 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, 271👍, 0💬

Using Cursors in SQL Server Transact-SQL
Where to find answers to frequently asked questions on Using Cursors in SQL Server Transact-SQL? I want to loop through rows in a result set. Here is a list of frequently asked questions and their answers compiled by FYIcenter.com DBA team on Using Cursors in SQL Server Transact-SQL. Clear explanati...
2016-10-17, 271👍, 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, 270👍, 0💬

Returning Top 5 Rows in MySQL
How To Return Top 5 Rows in MySQL? If you want the query to return only the first 5 rows, you can use the LIMIT clause, which takes one parameter as the maximum number of rows to return. The following statement returns the first 5 rows from the fyi_links: mysql&gt; SELECT id, url, counts, tag FR...
2017-12-21, 270👍, 0💬

UPDATE Subquery Returning Multiple Rows in SQL Server
What Happens If the UPDATE Subquery Returns Multiple Rows in SQL Server? If a subquery is used in a UPDATE statement, it must return exactly one row for each row in the update table that matches the WHERE clause. If it returns multiple rows, SQL Server will give you an error message. To test this ou...
2016-11-02, 270👍, 0💬

Defining and Using Table Alias Names in SQL Server
How To Define and Use Table Alias Names in SQL Server? When column names need to be prefixed with table names, you can define table alias name and use them to prefix column names. To define an alias for a table name, just enter the alias name right after the original table name in the FROM clause as...
2016-10-30, 270👍, 0💬

Returning the Second 5 Rows from a Query in SQL Server
How To Return the Second 5 Rows in SQL Server? If you want to display query output in multiple pages with 5 rows per page, and the visitor wants to see the output for the second page, you need to display query output from row 6 to row 10. If you are using MySQL server, you can use the "LIMIT startRo...
2016-10-29, 270👍, 0💬

Basic Features of a Trigger in SQL Server
What Are the Basic Features of a Trigger in SQL Server? Since a SQL Server trigger is a really an event handler, it has the following basic features similar to event handlers in other programming languages: Event Type - It must be declared to handle a specific event, like a DELETE event. Object Scop...
2016-10-25, 270👍, 0💬

Creating and Managing Schemas in SQL Server
Where to find answers to frequently asked questions on Creating and Managing Schemas in SQL Server? Here is a list of frequently asked questions and their answers compiled by FYIcenter.com DBA team on Creating and Managing Schemas in SQL Server. Clear answers are provided with tutorial exercises on ...
2016-10-22, 270👍, 0💬

"CREATE TRIGGER" - Creating a DDL Trigger in SQL Server
How To Create a DDL Trigger using "CREATE TRIGGER" Statements in SQL Server? A DDL trigger is defined to handle a DDL statement event, like create, alter and drop tables, views, indexes, etc. DDL triggers can be used to generate warning messages on database object changes. The format of creating a D...
2016-10-22, 270👍, 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&gt; INSERT INTO fyi_links (url, id) VALUES ('www.myspace.com', 301);...
2018-01-08, 269👍, 0💬

Accessing MySQL Server through Firewalls in MySQL
How To Access MySQL Servers through Firewalls in MySQL? If your MySQL server is provided by an Internet service company, connecting to the server from your local machine will not be so easy, because there are firewalls between your local machine and your MySQL server as shown below: As you can see, ...
2017-11-25, 269👍, 0💬

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