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Casting Strings to Wrong Code Pages in SQL Server Transact-SQL
What Happens If Strings Are Casted into Wrong Code Pages in SQL Server Transact-SQL? In SQL Server, different collations may use different code pages. For example: Albanian_CI_AI_KS_WS - Albanian, Code page 1250. Arabic_CI_AS_KS_WS - Arabic, Code page 1256. French_CI_AI - French, Code page 1252. Kor...
2017-05-13, 762👍, 0💬

"ALTER TABLE ... ADD" - Adding New Columns to Existing Tables in SQL Server
How To Add a New Column to an Existing Table with "ALTER TABLE ... ADD" in SQL Server? If you have an existing table with existing data rows, and want to add a new column to that table, you can use the "ALTER TABLE ... ADD" statement. The tutorial script below shows you a good example: ALTER TABLE t...
2016-11-17, 762👍, 0💬

sys.views - List of Existing Views in SQL Server
How To See Existing Views in SQL Server? If you want to know how many views you have created in a database, you use the system view called sys.views to get a list of views defined in the current database. The tutorial exercise shows you how many views in database FyiCenterData: USE FyiCenterData; GO...
2016-11-05, 762👍, 0💬

Convert Dates to Character Strings in Oracle
How To Convert Dates to Characters in Oracle? You can convert dates to characters using the TO_CHAR() function as shown in the following examples: SELECT TO_CHAR(SYSDATE, 'DD-MON-YYYY') FROM DUAL; -- SYSDATE returns the current date 07-MAY-2006 SELECT TO_CHAR(SYSDATE, 'YYYY/MM/DD') FROM DUAL; 2006/0...
2020-03-25, 761👍, 0💬

Use Group Functions in ORDER BY Clause in Oracle
Can Group Functions Be Used in the ORDER BY Clause in Oracle? 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 employees are having the same salary in each department. The group output is so...
2019-10-27, 761👍, 0💬

Define Anonymous Procedures with Variables in Oracle
How To Define an Anonymous Procedure with Variables in Oracle? Anonymous procedure is a procedure without any name. If you have some variables to declare, you can define an anonymous procedure by using the DECLARE keyword in SQL*Plus as shown in the following tutorial script: SQL&gt; set servero...
2018-01-27, 761👍, 0💬

Data Pump Export Utility in Oracle
What Is the Data Pump Export Utility in Oracle? Oracle Data Pump Export utility is a standalone programs that allows you to export data objects from Oracle database to operating system files called dump file set, which can be imported back to Oracle database only by Oracle Data Pump Import utility. ...
2016-10-15, 761👍, 0💬

Run Stored Procedures in Debug Mode in Oracle
How To Run Stored Procedures in Debug Mode in Oracle? If have an existing stored procedure and you want to debug it interactively, you can use the debug feature provided in SQL Developer. The following exercise shows you how to start the debug mode: Open you connection name, like Local_XE. Open Proc...
2019-01-12, 760👍, 0💬

Rename an Existing Column in a Table in MySQL
How To Rename an Existing Column in a Table in MySQL? If you have an existing column in a table and you want to change the column name, you can use the "ALTER TABLE ... CHANGE" statement. This statement allows you to change the name of a column, and its definition. The tutorial script below gives yo...
2018-03-04, 760👍, 0💬

Precision and Rounding of FLOAT Values in SQL Server Transact-SQL
How REAL and FLOAT Literal Values Are Rounded in SQL Server Transact-SQL? By definition, FLOAT(n) should store the mantissa of the floating number in n bits. For example, FLOAT(16) should have a precision one-byte less than FLOAT(24). However, SQL Server Transact-SQL only supports two precisions for...
2017-04-19, 760👍, 0💬

DECLARE Statements in SQL Server Transact-SQL
How to declare a variable in SQL Server Transact-SQL? How to use the DECLARE statements? In Transact-SQL, you must use DECLARE statements to declare variables. Declaring a variable is to define the variable name and the variable data type. In Transact-SQL, you can: Declare a single variable in a sin...
2017-04-04, 760👍, 0💬

What Is NULL Value in Oracle
What Is NULL Value in Oracle? NULL is a special value representing "no value" in all data types. NULL can be used on in operations like other values. But most operations has special rules when NULL is involved. The tutorial exercise below shows you some examples: SET NULL 'NULL'; -- Make sure NULL i...
2019-12-02, 759👍, 0💬

What Is a Subquery in Oracle
What Is a Subquery in Oracle? 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 eval...
2019-09-27, 759👍, 0💬

Rename an Index in Oracle
How To Rename an Index in Oracle? Let's say you have an existing index, and you don't like its name anymore for some reason, you can rename it with the ALTER INDEX ... RENAME TO statement. Here is an example script on how to rename an index: CREATE TABLE student (id NUMBER(5) PRIMARY KEY, first_name...
2019-05-01, 759👍, 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, 759👍, 0💬

PL/SQL Anonymous Block in Oracle
What Is an Anonymous Block in Oracle? An anonymous block is a PL/SQL code block with no name. It consists of three parts: Declaration Part - Defining local variables and local procedures. Declaration part is optional. Execution Part - Defining execution logic with executable statements. Execution pa...
2018-11-29, 758👍, 0💬

Parameter Modes Supported by PL/SQL in Oracle
What Are the Parameter Modes Supported by PL/SQL in Oracle? PL/SQL supports 3 parameter modes on procedure/function parameters: IN: This is the default mode. IN parameters allow the calling code to pass values into the procedure or function. OUT: OUT parameters allow the procedure or function to pas...
2018-10-19, 758👍, 0💬

Convert Times to Character Strings in Oracle
How To Convert Times to Character Strings in Oracle? You can convert dates to characters using the TO_CHAR() function as shown in the following examples: SELECT TO_CHAR(SYSDATE, 'HH:MI:SS') FROM DUAL; 04:49:49 SELECT TO_CHAR(SYSDATE, 'HH24:MI:SS.FF') FROM DUAL; -- Error: SYSDATE has no fractional se...
2019-12-02, 757👍, 0💬

Define Default Values for Formal Parameters in Oracle
How To Define Default Values for Formal Parameters in Oracle? If you have an IN parameter, you can make it as an optional parameter for the calling statement by defining the formal parameter with the DEFAULT clause. This gives you the freedom of not providing the actual parameter when calling this p...
2018-10-19, 757👍, 0💬

Tables Using CSV Storage Engine in MySQL
How To Create a New Table Using the CSV Storage Engine in MySQL? CSV (Comma-Separated Values) storage engine stores table data in text files in comma-separated value format. CSV is not the default storage engine. You need to specify "ENGINE = CSV" at the end of the "CREATE TABLE" statement to create...
2017-08-13, 757👍, 0💬

Variables and Data Types in SQL Server Transact-SQL
Where to find answers to frequently asked questions on variables and data types in Microsoft SQL Server Transact-SQL? I am new to Transact-SQL and SQL Server. Here is a list of frequently asked questions and their answers compiled by FYIcenter.com team on variables and data types in Microsoft SQL Se...
2017-04-22, 757👍, 0💬

CONVERT/CAST Function in SQL Server Transact-SQL
How to convert value from one data type to another in SQL Server Transact-SQL? How to use the CONVERT function or the CAST function? In Transact-SQL, you can use CONVERT statements to convert values from one data type to another, in the syntax of: CONVERT(data_type, value[, style]) In this syntax, "...
2017-04-01, 756👍, 0💬

Create a New Table in Your Schema in Oracle
How To Create a New Table in Your Schema in Oracle? If you want to create a new table in your own schema, you can log into the server with your account, and use the CREATE TABLE statement. The following script shows you how to create a table: &gt;.\bin\sqlplus /nolog SQL&gt; connect HR/fyice...
2019-06-01, 755👍, 0💬

Call Procedure or Function Recursively in Oracle
Can Sub Procedure/Function Be Called Recursively in Oracle? PL/SQL allows sub procedures or functions to be called recursively. The tutorial example below shows you how to calculate factorial values with a recursive sub function: SQL&gt; CREATE OR REPLACE PROCEDURE FACTORIAL_TEST AS 2 FUNCTION F...
2018-03-18, 755👍, 0💬

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