SELECT "column_name" FROM "table_name";
There are three ways we can retrieve data from a table:
- Retrieve one column
- Retrieve multiple columns
- Retrieve all columns
Let's use the following table to illustrate all three cases:
Table Store_Information
Store_Name | Sales | Txn_Date |
Los Angeles | 1500 | Jan-05-1999 |
San Diego | 250 | Jan-07-1999 |
Los Angeles | 300 | Jan-08-1999 |
Boston | 700 | Jan-08-1999 |
Select One Column
To select a single column, we specify the column name between SELECT and FROM as follows:
SELECT Store_Name FROM Store_Information;
Result:
Store_Name |
Los Angeles |
San Diego |
Los Angeles |
Boston |
Select Multiple Columns
We can use the SELECT statement to retrieve more than one column. To select Store_Name and Sales columns from Store_Information, we use the following SQL:
SELECT Store_Name, Sales FROM Store_Information;
Result:
Store_Name | Sales |
Los Angeles | 1500 |
San Diego | 250 |
Los Angeles | 300 |
Boston | 700 |
Select All Columns
There are two ways to select all columns from a table. The first is to list the column name of each column. The second, and the easier, way is to use the symbol *. For example, to select all columns fromStore_Information, we issue the following SQL:
SELECT * FROM Store_Information;
Result:
Store_Name | Sales | Txn_Date |
Los Angeles | 1500 | Jan-05-1999 |
San Diego | 250 | Jan-07-1999 |
Los Angeles | 300 | Jan-08-1999 |
Boston | 700 | Jan-08-1999 |
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