SQL Commands

The SQL SELECT Statement

The SELECT statement is used to select data from a table. The tabular result is stored in a result table (called the result-set).

Syntax

SQL SELECT Example

The Database table “eBIZ”

The Result

Select All Columns

To select all columns from the "eBIZ" table, use a * symbol instead of column names, like this:

The Result

The Result Set

The result from a SQL query is stored in a result-set. Most database software systems allow navigation of the result set with programming functions, like: Move-To-First-Record, Get-Record-Content, Move-To-Next-Record, etc.

Semicolon after SQL Statements?

Semicolon is the standard way to separate each SQL statement in database systems that allow more than one SQL statement to be executed in the same call to the server.

The SELECT DISTINCT Statement

The DISTINCT keyword is used to return only distinct (different) values. The SELECT statement returns information from table columns. But what if we only want to select distinct elements?

Syntax

Using the DISTINCT keyword

To select ALL values from the column named "Company" we use a SELECT statement like this:

“eBIZ student” table

Result

Note that "Upendra Mishra" is listed twice in the result-set.

To select only DIFFERENT values from the column named " Paid student " we use a SELECT DISTINCT statement like this:

Result

Now "Upendra mishra" is listed only once in the result-set