In this section, we will be discussing types of SQL commands. SQL Commands are divided into five broad categories – DDL, DML, DCL, TCL, and DQL. Each category is further explained below: 1. Data Definition Language(DDL): The Data Definition Language is made up of SQL commands that can ...
Syntax Select * from Table_Name; Example Select * from Student; SQL Copy DML(Data Manipulation Language) Command in SQL DML or Data Manipulation Language is to manipulate the data inside the database. With the help of DML commands, we can insert, delete, and change the data inside the ...
Syntax: ROLLBACK; Example:The following commands would have deleted all the students from theSTUDENTtable who have age greater than 15. Since we have used theROLLBACKcommand after the DELETE statement, these changes were undone and no record deleted from the table. The important point to note ...
DDL commands consist of different commands that have different functionalities, which I will discuss in the following order: DDL Command DESCRIPTION SYNTAX CREATE Create a table and its columns together with their datatype. CREATE TABLE ALTER
For example, if we want to add a new column e.g. ISBN to the existing Books table in the LibraryDB database, the ALTER command can be used as follows: 1 2 3 USELibraryDB ALTERTABLEBooks ADDISBNINTNOTNULL; The syntax of the ALTER command is straightforward. The ALTER statement is used...
CREATE TABLE my_table ( id INT CONSTRAINT positive_id CHECK (id > 0) , val INT CONSTRAINT val_in_range CHECK (val > 0 AND val < 1000) ); You can use table-level constraint syntax with the CHECK constraint, as shown in the following example. CREATE TABLE my_table ( id INT CONST...
Syntax refer【anyline-simple】 any questions, please contact skype:server@anyline.org QQ群(86020680)微信群过期请联系管理员 regardless of bugs, doubts, requirements, source code, competitors Introduction The core of AnyLine is a runtime oriented metadata dynamic relationship mapping primarily used for ...
HiveSQLLanguage Manual:Commands,CLIs,Data Types,DDL(create/drop/alter/truncate/show/describe),Statistics(analyze),Indexes,Archiving,DML(load/insert/update/delete/merge,import/export,explain plan),Queries(select),Operators and UDFs,Locks,Authorization ...
DDL statements in SQL primarily consist of the CREATE, ALTER, and DROP commands. Let's take a closer look at each of these commands and their usage.The CREATE command is used to createnew database objects such as tables, views, indexes, and stored procedures. For example, to create a ...
Syntax: Column level:COLUMN [data type] CONSTRAINT [name] [CHECK (condition)]Table level:CONSTRAINT [name] CHECK (condition)The following example shows how to use CHECK constraint at column level.CREATE TABLE TEST ( ..., GRADE char (1) CONSTRAINT TEST_CHK CHECK (upper (GRADE) in ('A',...