I’ll explain this by using examples in DDL, using SQL Server syntax. The short version of this is fairly simple. Every table that you want to use in relations should have a primary key constraint; this can either be a single field or a combination of fields defined by an expression. ...
SQL is classified into the following categories. Note that statements mentioned in the following tables may vary in different databases. CommandsDescription DDL Data Definition Language DML Data Manipulation Language TCL Transaction Control Language DCL Data Control Language ...
Oracle Database classifies and separates SQL statements into two distinct groups. These two groups are data manipulation language (DML) statements and data definition language (DDL) statements. There are two differences between DML and DDL statements. DML statements manipulate data. A DML statement ...
DQL is also a subset of SQL. One of the most common commands in DQL isSELECT. It lets users get data from a database table and perform some operation on it. When the statement is executed, the result is compiled into a
SQL is a non-procedural language. Each SQL statement is an individual execution unit, independent of other statements. There is no conditional statements, jumping statements or looping statements to group multiple statements together into a complex execution unit. There is no way to define a ...
Tables/Materialized Views (bring over full select statement) Functions/Procedures (bring over full parameter list) All other objects from Connections SQL from Reports Any files opened will be opened into a SQL Worksheet. The user will simply select the appropriate connection from the upper-right lis...
Data Definition Language (DDL)commands are also calleddata definition commandsbecause they are used to define data tables. Data Manipulation Language (DML)commands are used to manipulate data in existing tables by adding, changing or removing data. Unlike DDL commands that define how data is stored...
In SQL, lines starting with a double-dash ("--") are comments, and are not executed. Individual statements may span multiple lines, and each statement ends in a semicolon (";").-- DDL Example CREATE TABLE myTable ( myTableID INTEGER PRIMARY KEY AUTOINCREMENT, txtName CHAR(30) NOT NU...
To generate your DDL script, click on theSQLitem in the top bar; it will take you to the next screen,Generate SQL Script. Once there, indicate whether it is aCREATEorDROPDDL script (one serves to create the tables, the other to destroy them). ...
Tables/Materialized Views (bring over full select statement) Functions/Procedures (bring over full parameter list) All other objects from Connections SQL from Reports Any files opened will be opened into a SQL Worksheet. The user will simply select the appropriate connection from the upper-right lis...