What is the default sorting in MySQL?

What is the default sorting in MySQL?

By default, MySQL sorts all GROUP BY col1, col2, queries as if you specified ORDER BY col1, col2, in the query as well. However: Relying on implicit GROUP BY sorting in MySQL 5.5 is deprecated. To achieve a specific sort order of grouped results, it is preferable to use an explicit ORDER BY clause.

What is the default sort order for SQL?

By default ORDER BY sorts the data in ascending order. We can use the keyword DESC to sort the data in descending order and the keyword ASC to sort in ascending order.

How does MySQL choose which index to use?

If there is a choice between multiple indexes, MySQL normally uses the index that finds the smallest number of rows (the most selective index). If the table has a multiple-column index, any leftmost prefix of the index can be used by the optimizer to look up rows.

What is sorting in MySQL?

Sorting query results is re-arranging the rows returned from a query result set either in ascending or descending order. The keyword DESC in SQL, is used to sort the query result set in a descending order. The ASC keyword is used to sort the query result set in an ascending order.

How do you sort without an ORDER BY in SQL?

4 Answers

1. Use XML output and apply server-side XSLT transformation (through CLR for instance) with .
2. Use stored procedure to produce sorted list in one text return value.
3. Write own SQL proxy client replacing — HIDDEN MESSAGE with ORDER BY .

What is the default sorting order in SQL with null values?

If you specify the ORDER BY clause, NULL values by default are ordered as less than values that are not NULL. Using the ASC order, a NULL value comes before any non-NULL value; using DESC order, the NULL comes last.

How do I sort a column in MySQL?

When sorting your result set in descending order, you use the DESC attribute in your ORDER BY clause as follows: SELECT last_name, first_name, city FROM contacts WHERE last_name = ‘Johnson’ ORDER BY city DESC; This MySQL ORDER BY example would return all records sorted by the city field in descending order.

How are indexes used in MySQL for sorting?

Indexes are used not only for sorting, but for SELECTING. E.g. select * from mytable where id = 1 will use an index on the id column if there is one. Thanks for contributing an answer to Stack Overflow! Please be sure to answer the question.

How are data sorted in descending order in MySQL?

First, data sorted by Education in Descending Order and then sorted by Yearly Income in Descending Order. In this MySQL Order By Desc example, We are going to sort the table Data in Descending Order using the Alias Column Name.

What is the default order by of queries in MySQL?

On MySQL 5.6 they select in one order (the order of insertion), but in 4.1 they select backwards! This led to a very annoying deployment bug. I have’t found documentation on this change, but found notes on on implicit group order in MySQL:

What is the default index type for MySQL?

Clustered Indexes are the “default” from the perceptive of your question I guess might be a simple answer to your question but there is no default type of index. Clustered is the most common type of index, a Clustered Index is most often how the key or id of each row in a table in any relational database (MySQL, Sql Server etc) is indexed.