General MySQL Oracle SQL Server

<< < … 28 29 30 31 32 33 34 35 36 37 38 … > >>   ∑:1363  Sort:Date

Understanding and Managing Indexes in SQL Server
Where to find answers to frequently asked questions on Understanding and Managing Indexes in SQL Server? Here is a list of frequently asked questions and their answers compiled by FYIcenter.com DBA team on Understanding and Managing Indexes in SQL Server. Clear answers are provided with tutorial exe... 2016-11-15, 3135🔥, 0💬

Use IN Conditions in Oracle
How To Use IN Conditions in Oracle? An IN condition is single value again a list of values. It returns TRUE, if the specified value is in the list. Otherwise, it returns FALSE. Some examples are given in the script below: SELECT CASE WHEN 3 IN (1,2,3,5) THEN 'TRUE' ELSE 'FALSE' END FROM DUAL; TRUE S... 2020-03-15, 3133🔥, 0💬

What Is a Dead Lock in MySQL
What Is a Dead Lock in MySQL? A dead lock is phenomenon happens between two transactions with each of them holding a lock that blocks the other transaction as shown in the following diagram: (transaction 1) (transaction 2) update row X to create lock 1 update row Y to create lock 2 update row X (blo... 2017-04-28, 3133🔥, 0💬

Triggers with Multiple Affected Rows in SQL Server
What Happens to a Trigger with Multiple Affected Rows in SQL Server? If there is only one row affected by a DML statement, we know that the DML trigger will be executed once. But how many times the DML trigger will be executed if the DML statement resulted multiple affected rows? The answer is still... 2016-10-24, 3132🔥, 0💬

Differences of CHAR and VARCHAR in SQL Server Transact-SQL
What Are the Differences between CHAR and VARCHAR in SQL Server Transact-SQL? CHAR and VARCHAR are both used to store code page based 1-byte character strings in Transact-SQL. But they have the following main differences: CHAR(n) stores character strings with a fixed length, n bytes, storage format.... 2017-04-04, 3131🔥, 0💬

Scope of Local Variables in Oracle
What Is the Scope of a Local Variable in Oracle? The scope of a variable can be described with these rules: A variable is valid within the procedure or function where it is defined. A variable is also valid inside a sub procedure or function defined. If a variable name is collided with another varia... 2018-10-13, 3129🔥, 0💬

What Is a Subquery in MySQL
What Is a Subquery in MySQL? A subquery is a SELECT statement used as part of the selection criteria of the main SELECT statement. The subquery specified in the WHERE clause will be evaluated repeated on each row of the selection base table. The output of the subquery will be used in the final evalu... 2017-09-17, 3129🔥, 0💬

Drop an Existing View in Oracle
How To Drop an Existing View in Oracle? If you have an existing view, and you don't want it anymore, you can delete it by using the DROP VIEW statement as shown in the following script: DROP VIEW employee_department; View dropped.   ⇒ Understanding SQL DML Statements for Oracle ⇐ Create a New View ... 2020-02-07, 3128🔥, 0💬

Open and Close an Explicit Cursor in Oracle
How To Open and Close an Explicit Cursor in Oracle? An existing cursor can be opened or closed by the OPEN or CLOSE statement as shown in the following sample script: DECLARE CURSOR c_list IS SELECT * FROM countries; CURSOR t_list IS SELECT * FROM employees WHERE employee_id = 100; BEGIN OPEN c_list... 2018-07-22, 3128🔥, 0💬

Tables Using MyISAM Storage Engine in MySQL
How To Create a New Table Using MyISAM Storage Engine in MySQL? MyISAM storage engine is based on the ISAM (Indexed Sequential Access Method) concept, which was first developed at IBM to store and retrieve data on secondary storage systems like tapes. MyISAM storage engine offers fast data storage a... 2017-09-12, 3128🔥, 0💬

PL/SQL Functions in Oracle
What Is a Function in Oracle? A function is a named program unit. It consists of three parts: Declaration Part - Defining the function name, calling parameters, return value type, local variables and local procedures. Declaration part is required. Execution Part - Defining execution logic with execu... 2018-11-29, 3127🔥, 0💬

Sort Query Output in Descending Order in Oracle
How To Sort Query Output in Descending Order in Oracle? 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 department in descending order, then sorts the salary in ascending order: SQL&gt; SELE... 2019-12-19, 3126🔥, 0💬

Inner Join with the WHERE Clause in MySQL
How To Write an Inner Join with the WHERE Clause in MySQL? 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: mysql&gt; SELECT l.id, l.url, r.comment FROM fyi_links l, fyi_rates... 2017-09-28, 3124🔥, 0💬

Creating User Defined Functions with Parameters in SQL Server
How To Create User Defined Functions with Parameters in SQL Server Transact-SQL? Very often, you need to create a function with one or more parameters so that the function can be more generic. You only supply values to those parameters at the time of executing the function. User defined functions wi... 2016-12-18, 3123🔥, 0💬

Drop a Tablespace in Oracle
How To Drop a Tablespace in Oracle? If you have an existing tablespace and you don't want it anymore. You can delete a tablespace by using the DROP TABLESPACE statement as shown in the example below: SQL&gt; CREATE TABLESPACE my_space 2 DATAFILE '/temp/my_space.dbf' SIZE 10M; Tablespace created.... 2019-04-13, 3122🔥, 0💬

Define Anonymous Procedures without Variables in Oracle
How To Define an Anonymous Procedure without Variables in Oracle? Anonymous procedure is a procedure without any name. If you don't have any variables to declare, you can define an anonymous procedure by using the BEGIN keyword directly in SQL*Plus as shown in the following tutorial script: SQL&... 2018-01-27, 3117🔥, 0💬

Rename an Existing Table in Oracle
How To Rename an Existing Table in Oracle? If you don't like the name of an existing table, you change it by using the CREATE TABLE ... RENAME TO statement. Here is a sample script: SQL&gt; connect HR/fyicenter Connected. SQL&gt; CREATE TABLE emp_dept_10 2 AS SELECT * FROM employees WHERE de... 2019-06-01, 3116🔥, 0💬

Read Consistency Support in MySQL in MySQL
How Does MySQL Handle Read Consistency in MySQL? Read consistency is a concept that describes how consistent the output will be on two subsequent read operations. A read operation is usually a stand alone SELECT statement or a SELECT subquery in a parent statement. A database server can support up t... 2017-08-03, 3116🔥, 0💬

Repair MyISAM Tables in MySQL
How To Check and Repair MyISAM Tables in MySQL? If you have a corrupted MyISAM table, like the one resulted from the previous tutorial exercise, you can use the "CHECK TABLE" and "REPAIR TABLE" commands to try to repair it. The following tutorial exercise gives you a good example of repairing a corr... 2017-09-01, 3115🔥, 0💬

"CREATE TABLE" Statement - Creating New Tables in SQL Server
How to create new table with "CREATE TABLE" statements in SQL Server? This is the second tutorial of a quick lesson on creating database objects with Transact-SQL statements. This lesson shows you how to create a database, create a table in the database, and then access and change the data in the ta... 2016-12-02, 3115🔥, 0💬

Establish Administrator Authentication to the Server in Oracle
How To Establish Administrator Authentication to the Server in Oracle? This is Step 2. There are two ways to establish administrator authentication to a new database. Use a password file. Use operating system (OS) authentication. Using OS authentication is easier on Windows system. If you used your ... 2019-04-03, 3112🔥, 0💬

Create a New User Account in Oracle
How To Create a New User Account in Oracle? If you want to create a new user account, you can log in as SYSTEM and use the CREATE USER command as shown in the following example: &gt;.\bin\sqlplus /nolog SQL&gt; connect SYSTEM/fyicenter Connected. SQL&gt; CREATE USER DEV IDENTIFIED BY dev... 2019-07-21, 3111🔥, 0💬

What Are DDL Statements in MySQL
What Are DDL Statements in MySQL? DDL (Data Definition Language) statements are statements to create and manage data objects in the database. The are 3 primary DDL statements: CREATE - Creating a new database object. ALTER - Altering the definition of an existing data object. DROP - Dropping an exis... 2018-03-10, 3111🔥, 0💬

SGA Setting Is Too Low in Oracle
What Happens If You Set the SGA Too Low in Oracle? Let's you made a mistake and changed to SGA to 16MB from the SYSTEM admin home page. When you run the batch file StartDB.bat, it will return a message saying server stated. However, if you try to connect to your server home page: http://localhost:80... 2020-09-30, 3110🔥, 0💬

<< < … 28 29 30 31 32 33 34 35 36 37 38 … > >>   ∑:1363  Sort:Date

General MySQL Oracle SQL Server