General MySQL Oracle SQL Server

<< < … 33 34 35 36 37 38 39 40 41 42 43 … > >>   ∑:1363  Sort:Date

in Oracle
How To Delete All Rows from a Table in Oracle? 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 exa... 2020-01-04, 2840🔥, 0💬

Evaluating Expressions with SELECT Statements in MySQL
How To Calculate Expressions with SELECT Statements in MySQL? There is no special SQL statements to calculate expressions. But you can use the "SELECT expression FROM DUAL" statement return the calculated value of an expression. "DUAL" is a dummy table in the server. The tutorial exercise below show... 2018-04-12, 2839🔥, 0💬

Retrieve Data from an Explicit Cursor in Oracle
How To Retrieve Data from an Explicit Cursor in Oracle? If you have a cursor opened ready to use, you can use the FETCH ... INTO statement to retrieve data from the cursor into variables. FETCH statement will: Retrieve all the fields from the row pointed by the current cursor pointer and assign them... 2018-07-22, 2838🔥, 0💬

Run Stored Procedures Interactively in Oracle
How To Run a Stored Procedure Interactively in Oracle? If have an existing stored procedure and you want to run it interactively, the tutorial steps listed below will help you out: Open you connection name, like Local_XE. Open Procedures. Right-click the procedure name: HELLO. Select Run. The Run PL... 2019-01-12, 2837🔥, 0💬

Convert Character Types to Numeric Types in Oracle
How To Convert Character Types to Numeric Types in Oracle? You can convert character types to numeric types in two ways: Explicitly by using TO_NUMBER() function. Implicitly by putting character data in a numeric operation. The sample script below shows you how to convert character types to numeric ... 2018-11-17, 2837🔥, 0💬

Query with a Right Outer Join in Oracle
How To Write a Query with a Right Outer Join in Oracle? 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: departments and employees. The join con... 2019-10-18, 2836🔥, 0💬

Create a Table Interactively in Oracle
How To Create a Table Interactively in Oracle? If you don't want to use SQL statements to create a new table, you use SQL Developer to create one interactively. Follow the steps below to create a new table called: TIP Right-click on the Tables in the object tree area. Select Create TABLE. Create Tab... 2018-10-08, 2836🔥, 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, 2834🔥, 0💬

Giving Privileges at Server Level in MySQL
How To Grant User Privileges at the Global Level in MySQL? If you want to grant a user privilege at the global level, you can use the "GRANT privilegeName ON *.* TO userName" command. The argument "*.*" in the command stands for all database and all tables. The following tutorial exercise shows you ... 2017-08-21, 2834🔥, 0💬

Primary Key - Default Indexes of Tables in SQL Server
Is the PRIMARY KEY Column of a Table an Index in SQL Server? If you define a primary key on a table, an index for the primary key column will be created by default. The tutorial exercise below shows you the index created as part of the primary key column of "fyi_links": USE FyiCenterData; GO -- Drop... 2016-11-13, 2832🔥, 0💬

What Is a SELECT Query Statement in Oracle
What Is a SELECT Query Statement in Oracle? 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... 2020-01-04, 2831🔥, 0💬

UNIQUE Constraint Creating Default Index in SQL Server
Does the UNIQUE Constraint Create an Index in SQL Server? If you add the UNIQUE constraint on a column, SQL Server will automatically add a non-clustered index for that column. The tutorial exercise below shows you the index created as part of the UNIQUE column, "id", of "fyi_links": USE FyiCenterDa... 2016-11-13, 2831🔥, 0💬

Invoke Built-in Functions in PL/SQL in Oracle
How To Invoke Built-in Functions in PL/SQL in Oracle? Of course, you can invoke SQL functions in SQL statements. But many SQL functions can also be executed in regular PL/SQL statements, as shown in the following sample script: DECLARE now DATE; id NUMBER; str VARCHAR2(40); BEGIN now := SYSDATE; DBM... 2018-09-13, 2829🔥, 0💬

Using CASE Expression in MySQL
How To Use CASE Expression in MySQL? There are 2 ways to use the CASE expression. The first way is to return one of the predefined values based on the comparison of a given value to a list of target values. The second way is to return one of the predefined values based on a list of conditions. Here ... 2018-03-24, 2829🔥, 0💬

Drop an Existing View in MySQL
How To Drop an Existing View in MySQL? If you have an existing view, and you don't want it anymore, you can delete it by using the "DROP VIEW viewName" statement as shown in the following script: mysql&gt; DROP VIEW faqComment; Query OK, 0 rows affected (0.00 sec) mysql&gt; SELECT * FROM faq... 2018-01-24, 2829🔥, 0💬

Experiment with Data Locks in MySQL
How To Experiment Data Locks in MySQL? If you want to have some experience with data locks, you can create two windows running two mysql transactions in two sessions. In session 1, you can run a UPDATE statement with REPEATABLE READ transaction isolation level to create an exclusive lock. Before com... 2017-04-28, 2829🔥, 0💬

What Are Stored Procedures in SQL Server
What Are Stored Procedures in SQL Server Transact-SQL? A stored procedure is a collection of Transact-SQL statements that stored in the SQL Server. A stored procedure can be executed later with an EXEC statement. SQL Server supports stored procedures with the following features: 1. Stored procedures... 2017-01-11, 2829🔥, 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, 2828🔥, 0💬

Selecting an Existing Database in MySQL
How To Select an Exiting Database in MySQL? The first thing after you have created a connection object to the MySQL server is to select the database where your tables are located, by using the mysql_select_db() function. If your MySQL server is offered by your Web hosting company, they will assign a... 2017-10-23, 2827🔥, 0💬

SINGLE_USER/MULTI_USER - Database User Access Options in SQL Server
How to set database to be SINGLE_USER in SQL Server? Databases in SQL Server have three user access options: MULTI_USER - All users that have the appropriate permissions to connect to the database are allowed. This is the default. SINGLE_USER - One user at a time is allowed to connect to the databas... 2016-11-20, 2827🔥, 0💬

What Is a Transaction in Oracle
What Is a Transaction in Oracle? A transaction is a logical unit of work requested by a user to be applied to the database objects. Oracle server introduces the transaction concept to allow users to group one or more SQL statements into a single transaction, so that the effects of all the SQL statem... 2019-09-16, 2826🔥, 0💬

What Are User Privileges in MySQL
What Are User Privileges in MySQL? MySQL offers many user privileges to control user accesses to different functions and data objects. Here are some commonly used privileges: ALL - All privileges. CREATE - Allows the user to use CREATE TABLE commands. ALTER - Allows the user to use ALTER TABLE comma... 2017-12-09, 2826🔥, 0💬

Differences of CHAR and NCHAR in SQL Server Transact-SQL
What Are the Differences between CHAR and NCHAR in SQL Server Transact-SQL? Both CHAR and NCHAR are fixed length data types in Transact-SQL. But they have the following main differences: CHAR stores characters based on the code page with 1 byte per character most of the time. NCHAR stores characters... 2017-04-04, 2826🔥, 0💬

Simplest Tool to Run Commands on Oracle Server in Oracle
What Is the Simplest Tool to Run Commands on Oracle Servers in Oracle? The simplest tool to connect to an Oracle server and run commands to manage data is SQL*Plus. It is an Oracle database client tool that works as a command-line user interface to the database server. SQL*Plus allows you: Format, p... 2018-06-27, 2824🔥, 0💬

<< < … 33 34 35 36 37 38 39 40 41 42 43 … > >>   ∑:1363  Sort:Date

General MySQL Oracle SQL Server