General MySQL Oracle SQL Server

<< < … 35 36 37 38 39 40 41 42 43 44 45 … > >>   ∑:1360  Sort:Date

Adding a New Index to a Large Table in SQL Server
What Happens If You Add a New Index to Large Table in SQL Server? An index can be added when you create a new table. New rows will be indexed as they are inserted into the table. But you can also add a new index to an existing table with the same CREATE INDEX statement. The existing rows will be ind... 2016-11-13, 2613🔥, 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, 2612🔥, 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, 2612🔥, 0💬

Add Another Datafile to a Tablespace in Oracle
How To Add Another Datafile to a Tablespace in Oracle? If you created a tablespace with a data file a month ago, now 80% of the data file is used, you should add another data file to the tablespace. This can be done by using the ALTER TABLESPACE ... ADD DATAFILE statement. See the following sample s... 2019-04-09, 2609🔥, 0💬

System Databases Used by SQL Servers in SQL Server
What are system databases in SQL Server? System databases are created by the SQL Server itself during the installation process. System databases are used by the SQL server to help manage other user databases and client execution sessions. SQL Server 2005 Express Edition uses 4 system databases: mast... 2016-11-20, 2609🔥, 0💬

PHP MSSQL - Query Multiple Tables Jointly
PHP MSSQL - How To Query Multiple Tables Jointly? If you want to query information stored in multiple tables, you can use the SELECT statement with a WHERE condition to make an inner join. Assuming that you have 3 tables in a forum system: "users" for user profile, "forums" for forums information, a... 2024-02-09, 2608🔥, 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, 2607🔥, 0💬

What Is Index in MySQL
What Is Index in MySQL? An index is a single column or multiple columns defined to have values pre-sorted to speed up data retrieval speed.   ⇒ What Is View in MySQL ⇐ What Is Foreign Key in MySQL ⇑ Database Basics and Terminologies in MySQL ⇑⇑ MySQL Database Tutorials 2017-07-07, 2607🔥, 0💬

Assign a Table Row to RECORD Variable in Oracle
How To Assign a Table Row to a RECORD Variable in Oracle? If you have a table, and want to assign a data row of that table to a RECORD variable, you need to define this RECORD variable to match the table column structure, then use the SELECT ... INTO statement to assign a data row that RECORD variab... 2018-08-14, 2606🔥, 0💬

What Are DML Statements in MySQL
What Are DML Statements in MySQL? DML (Data Manipulation Language) statements are statements to change data values in database tables. The are 3 primary DML statements: INSERT - Inserting new rows into database tables. UPDATE - Updating existing rows in database tables . DELETE - Deleting existing r... 2018-01-24, 2606🔥, 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, 2603🔥, 0💬

Creating a New Table in MySQL
How To Create a New Table in MySQL? If you want to create a table, you can run the CREATE TABLE statement as shown in the following sample script: &lt;?php include "mysql_connection.php"; $sql = "CREATE TABLE fyi_links (" . " id INTEGER NOT NULL" . ", url VARCHAR(80) NOT NULL" . ", notes VARCHAR... 2017-10-08, 2603🔥, 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, 2603🔥, 0💬

Use Subqueries with the IN Operator in Oracle
How To Use Subqueries with the IN Operator in Oracle? 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 how to ... 2019-09-27, 2602🔥, 0💬

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, 2602🔥, 0💬

Creating a View with Data from Another View in SQL Server
Can You Create a View using Data from Another View in SQL Server? Can You Create a View with Data from Another View? The answer is yes. A view can be used as a table to build other views. The tutorial exercise below shows you how to create a view using data from another view: USE AdventureWorksLT; G... 2016-11-05, 2602🔥, 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, 2601🔥, 0💬

Index Speeding Up SELECT Statements in SQL Server
Does Index Speed Up SELECT Statements in SQL Server? If you want to see the impact of indexes on SELECT statements, you can run the same SELECT statement on "fyi_links" and "fyi_links_indexed" tables. See the tutorial exercise below: USE FyiCenterData; GO -- Run SELECT on the table without indexes D... 2016-11-13, 2601🔥, 0💬

Define a Variable to Match Column Data Type in Oracle
How To Define a Variable to Match a Table Column Data Type in Oracle? If you have a table, and want to define some variables to have exactly the same data types as some columns in that table, you can use table_name.column_name%TYPE as data types to define those variables. The tutorial sample below s... 2018-08-14, 2600🔥, 0💬

Run the Anonymous Block Again in Oracle
How To Run the Anonymous Block Again in Oracle? If you have an anonymous block defined in your session, you can run it any time by using the "/" command as shown in the following script: SQL&gt; set serveroutput on; SQL&gt; begin 2 dbms_output.put_line('This is a PL/SQL FAQ.'); 3 end; 4 / Th... 2018-10-30, 2599🔥, 0💬

Numeric Comparison Operations in Oracle
What Are the Numeric Comparison Operations in Oracle? PL/SQL supports 6 basic numeric comparison operations as shown in the following sample script: PROCEDURE proc_comparison AS res BOOLEAN; BEGIN res := 1 = 2; res := 1 &lt; 2; res := 1 &gt; 2; res := 1 &lt;= 2; res := 1 &gt;= 2; res... 2018-08-06, 2599🔥, 0💬

UPDATE Subquery Returning No Rows in SQL Server
What Happens If the UPDATE Subquery Returns No Rows in SQL Server? If you use a subquery to assign new values in the SET clause in an UPDATE statement, and the subquery returns no rows for an outer row, SQL Server will provide a NULL value to the SET clause. The tutorial exercise below shows you a g... 2016-11-02, 2599🔥, 0💬

Create a Stored Procedure Interactively in Oracle
How To Create a Procedure Interactively in Oracle? If you want to create a stored procedure interactively, you can use the following steps: Open you connection name, like Local_XE. Right-click Procedures. Select Create PROCEDURE. The Create Procedure window shows up. Enter Name as: Hello Click OK. T... 2019-01-12, 2598🔥, 0💬

Converting Numeric Expressions from One Data Type to Another in SQL Server
How To Convert a Numeric Expression from One Data Type to Another in SQL Server Transact-SQL? There are 4 ways to convert a numeric expression from one data type to another data type: Implicit conversion by arithmetic operations - When arithmetic operations are performed on expressions of different ... 2017-03-27, 2598🔥, 0💬

<< < … 35 36 37 38 39 40 41 42 43 44 45 … > >>   ∑:1360  Sort:Date

General MySQL Oracle SQL Server