SQL statements that prevent repeated data in Multi-table queries in thinkphp (mandatory) and thinkphpsql

SQL statements that prevent repeated data in Multi-table queries in thinkphp (mandatory) and thinkphpsql

Let's take a look at the example below:

Tableid name1 a2 b3 c4 c5 B

The library structure is like this. This is just a simple example, and the actual situation is much more complicated.

Select *, count (distinct name) from table group by name

Result:

Id name count (distinct name) 1 a 12 B 13 c 1

The last item is redundant.

You can see the relevant information for consistent operations in tp2.0 manual search.

SELECT cat_id, COUNT (*) AS goods_num FROM talble group by cat_id $ M = M ('table '); $ rs = $ M-> field (array ('cat _ id', 'count (*) '=> 'goods _ num ')) -> group ('cat _ id')-> select (); echo $ M-> getLastSQL (); print_r ($ rs );

The above is all the content of the SQL statement (mandatory) that prevents data duplication in Multi-table queries in thinkphp provided by xiaobian. I hope it will help you and support more help ~