General MySQL Oracle SQL Server

<< < … 35 36 37 38 39 40 41 42 43 44 45 … > >>   ∑:1363  Sort:Date

What Is an External Table in Oracle
What Is an External Table in Oracle? An external table is a table defined in the database with data stored outside the database. Data of an external table is stored in files on the operating systems. Accessing data of external tables are done through data access drivers. Currently, Oracle supports t... 2016-11-27, 2804🔥, 0💬

Database Engine Tutorials from SQL Server 2005 Books Online
How to use Transact-SQL statements to access the database engine in SQL Server? Transact-SQL statements can be used to access the database engine directly. Here are some good tutorials provided by the SQL Server 2005 Books Online. See the SQL Server 2005 Tutorials &gt; Database Engine Tutorials ... 2016-11-27, 2804🔥, 0💬

PL/SQL 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... 2018-11-29, 2803🔥, 0💬

Create a Test Table for DML Testing in Oracle
How To Create a Testing Table in Oracle? If you want to practice DML statements, you should create a testing table as shown in the script below: CREATE TABLE fyi_links (id NUMBER(4) PRIMARY KEY, url VARCHAR2(80) NOT NULL, notes VARCHAR2(1024), counts NUMBER, created DATE DEFAULT (sysdate)); Table cr... 2020-02-07, 2802🔥, 0💬

Create a Single Index for Multiple Columns in Oracle
How To Create a Single Index for Multiple Columns in Oracle? If you know a group of multiple columns will be always used together as search criteria, you should create a single index for that group of columns with the "ON table_name(col1, col2, ...)" clause. Here is an example of one index for two c... 2019-04-17, 2802🔥, 0💬

Deleting Existing Rows in MySQL
How To Delete Existing Rows in a Table in MySQL? If you want to remove a row from a table, you can use the DELETE statement with a WHERE clause to identify the row. The following sample script deletes one row: &lt;?php include "mysql_connection.php"; $sql = "DELETE FROM fyi_links WHERE id = 1102... 2017-06-28, 2802🔥, 0💬

Define a Data Field as NOT NULL in Oracle
How To Define a Data Field as NOT NULL in Oracle? When defining a specific RECORD type, you can define a data field as NOT NULL to make sure variables with this RECORD type to always have values in this field. A field defined as NOT NULL must have a default value. Here is a tutorial script showing y... 2018-09-01, 2801🔥, 0💬

Creating Databases with Specified Physical Files in SQL Server
How to create database with physical files specified in SQL Server? If you don't like the default behavior of the CREATE DATABASE statement, you can specify the physical database files with a longer statement: CREATE DATABASE database_name ON (NAME = logical_data_name, FILENAME = physical_data_name,... 2016-11-24, 2801🔥, 0💬

What Is Oracle Server Autotrace in Oracle
What Is Oracle Server Autotrace in Oracle? Autotrace is Oracle server feature that generates two statement execution reports very useful for performance tuning: Statement execution path - Shows you the execution loop logic of a DML statement. Statement execution statistics - Shows you various execut... 2020-06-08, 2800🔥, 0💬

Major Storage Engines Supported in MySQL in MySQL
What Are Storage Engines in MySQL? Storage engines are programs that are integrated into MySQL database management system to manage data tables. MySQL 5.0 supports the following major storage engines: MyISAM Storage Engine - MySQL default storage engine. Based on ISAM database concept. MyISAM is not... 2017-09-12, 2800🔥, 0💬

CASE - Conditional Expressions in SQL Server
What Are Conditional Expressions in SQL Server Transact-SQL? A conditional expression returns one of the given expressions based a specific condition. SQL Server 2005 offers the CASE operator to present a conditional expression with two syntaxes: 1. CASE with simple conditions CASE test_value WHEN v... 2017-01-29, 2800🔥, 0💬

Use Subqueries in the FROM Clause in Oracle
How To Use Subqueries in the FROM Clause in Oracle? If you have a query returning many rows of data, and you want to perform another query on those rows, you can put the first query as a subquery in the FROM clause of the second query. The following statement shows you how to use a subquery as base ... 2019-09-27, 2799🔥, 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, 2798🔥, 0💬

What Is Row in MySQL
What Is Row in MySQL? A row is a unit of data with related data items stored as one item in one column in a table.   ⇒ What Is Primary key in MySQL ⇐ What Is Column in MySQL ⇑ Database Basics and Terminologies in MySQL ⇑⇑ MySQL Database Tutorials 2017-07-15, 2798🔥, 0💬

Performing Comparison on Floating Point Numbers in SQL Server
How To Perform Comparison on Floating Point Numbers in SQL Server Transact-SQL? Comparison operations on approximate (floating point) numbers are also easy to understand. Just watch out rounding operations performed during conversions. Here are two examples of floating point number comparisons: -- R... 2017-01-21, 2798🔥, 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, 2798🔥, 0💬

DROP TABLE Statement in Oracle
How To Drop an Existing Table in Oracle? If you want to delete an existing table and its data rows, you can use the DROP TABLE statement as shown in this script: SQL&gt; connect HR/fyicenter Connected. SQL&gt; CREATE TABLE emp_dept_10 2 AS SELECT * FROM employees WHERE department_id=10; Tabl... 2020-02-20, 2796🔥, 0💬

Memory Usage of the MySQL Server in MySQL
How Much Memory Does the Server Take in MySQL? If you are interested to know how much memory your MySQL server is taking, you can use Windows Task Manager to find out. Try to following this tutorial exercise: Start your MySQL server. Press Ctrl-Alt-Del and click Task Manager. The Task Manager window... 2017-12-04, 2796🔥, 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, 2796🔥, 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, 2793🔥, 0💬

Create a New Table by Selecting Rows from Another Table in Oracle
How To Create a New Table by Selecting Rows from Another Table in Oracle? Let's say you have a table with many data rows, now you want to create a backup copy of this table of all rows or a subset of them, you can use the CREATE TABLE...AS SELECT statement to do this. Here is an example script: &... 2019-06-01, 2792🔥, 0💬

Predefined User Accounts in MySQL
What Are the Predefined User Accounts in MySQL? There is only one predefined user account called "root": "root" was created during the installation process. "root" has no password initially. You need to assign a new password as soon as you finishes the installation. "root" has all access privileges ... 2017-09-08, 2792🔥, 0💬

Define an Explicit Cursor in Oracle
How To Define an Explicit Cursor in Oracle? An explicit cursor must be defined in the declaration part of a procedure or function with the CURSOR ... IS statement as shown in the following sample script: DECLARE CURSOR c_list IS SELECT * FROM countries; CURSOR t_list IS SELECT * FROM employees WHERE... 2018-07-22, 2790🔥, 0💬

Using Regular Expression with REGEXP in MySQL
How To Use Regular Expression in Pattern Match Conditions in MySQL? If you have a pattern that is too complex for LIKE to handle, you can use the regular expression pattern condition: REGEXP. The following tutorial exercise provides you some good examples: SELECT 'FYICenter.com' REGEXP '.*fyi.*' FRO... 2018-03-24, 2790🔥, 0💬

<< < … 35 36 37 38 39 40 41 42 43 44 45 … > >>   ∑:1363  Sort:Date

General MySQL Oracle SQL Server