Running Queries

The Running Queries section describes the following:

• Running basic queries

• Outputting all columns

• Outputting shorthand table values

• Filtering results

• Sorting results

• Filtering null rows

Running Basic Queries

You can run a basic query using the SELECT keyword, followed by a list of columns and values to be returned, and the table to get the data from, as shown in the following example:

SELECT id, name, weight FROM cool_animals;
1,Dog                 ,7
2,Possum              ,3
3,Cat                 ,5
4,Elephant            ,6500
5,Rhinoceros          ,2100
6,\N,\N

For more information on the SELECT keyword, see SELECT.

To Output All Columns

You can output all columns without specifying them using the star operator *, as shown in the following example:

SELECT * FROM cool_animals;
1,Dog                 ,7
2,Possum              ,3
3,Cat                 ,5
4,Elephant            ,6500
5,Rhinoceros          ,2100
6,\N,\N

Outputting Shorthand Table Values

You can output the number of values in a table without getting the full result set by using the COUNT statement:

SELECT COUNT(*) FROM cool_animals;
6

Filtering Results

You can filter results by adding a WHERE clause and specifying the filter condition, as shown in the following example:

SELECT id, name, weight FROM cool_animals WHERE weight > 1000;
4,Elephant            ,6500
5,Rhinoceros          ,2100

Sorting Results

You can sort results by adding an ORDER BY clause and specifying ascending (ASC) or descending (DESC) order, as shown in the following example:

SELECT * FROM cool_animals ORDER BY weight DESC;
4,Elephant            ,6500
5,Rhinoceros          ,2100
1,Dog                 ,7
3,Cat                 ,5
2,Possum              ,3
6,\N,\N

Filtering Null Rows

You can filter null rows by adding an IS NOT NULL filter, as shown in the following example:

SELECT * FROM cool_animals WHERE weight IS NOT NULL ORDER BY weight DESC;
4,Elephant            ,6500
5,Rhinoceros          ,2100
1,Dog                 ,7
3,Cat                 ,5
2,Possum              ,3

For more information, see the following:

• Outputting the number of values in a table without getting the full result set - COUNT(*).

• Filtering results - WHERE

• Sorting results - ORDER BY

• Filtering rows - IS NOT NULL