Select & Sort

Selecting

The SELECT query selects a specific field (column) from a specific table. The semicolon ; is required at the end of every SQL query.

-- sample syntax for select
SELECT [field]
FROM [table];

Adding multiple columns after SELECT will return data from multiple columns.

-- sample syntax for selecting multiple fields
SELECT [field_1], [field_2], [field_3]
FROM [table];

SELECT DISTINCT

We might want to write a query to return all the unique values in a particular field. For example, selecting the entire country field in the Player_Birthplaces table would return many duplicate values.

-- sample syntax for selecting unique values
SELECT DISTINCT [field]
FROM [table];

SELECT DISTINCT returns a list of unique values.

Sorting

We might also want to sort the results returned by a query.

-- sample syntax that selects all values from a table and orders by specific file
SELECT *
FROM [table]
ORDER BY [field] ASC;

The * wildcard operator selects all the fields in a specific table. ORDER BY specifies a field to use in sorting the query results. ASC returns ascending results. DESC would return descending results.

We can also sort on multiple fields.

-- sample syntax that selects all values from a table and orders by two fields
SELECT *
FROM [table]
ORDER BY [field_1] ASC, [field_2] DESC;

In the query above, the ORDER BY statement sorts [field_1] first (ascending) and then sorts [field_2] (descending).