1, the inner join query: inner join ... on
Only the records meet the conditions to be able to appear in the result of the relationship, that is exactly equal. Self-join queries is a special inner join query.
2, outer join query:
1 "left outer connecting / left connecting: Returns all records including records left table and the right table in connection equivalent field.
2 "right outer connector / Right connection: Returns all records including records left table and the right table in connection equivalent field.
3 "Full outer join: return all the data records in both tables.
3, sub-queries
Subquery operators are commonly used: any (some), all, in, exists.
1》any（some）：
select * from t1 where t1.id > any (select id from t2 where t2.name=...)
2 "all: supra, it can be used with comparison operators.
3》exists / not exists：
4》in / not in：
5 "comparison operator with subqueries: <, <=, =,> = ,! = (Or <>)
6 "union / union all: consolidated results
4, the regular expression query
MySQL uses pattern matching characters specified regular expression regexp keyword, the default is not case-sensitive.
Matches the specified string: as long as the string to the query text. If a plurality of strings to be matched between a plurality of strings using separators '|' apart.
select * from test where name regexp 'or|ap';
Matches the specified string in any one of: a square brackets "[]" to specify a set of characters, wherein only match any character , text that is looking for.
select * from test where name regexp '[orap]';
SELECT * from Test WHERE name regexp '[0-9] | [AZ]' ; // [] may be in the range
Matching characters other than the specified characters:
select * from test where name regexp '[^a-z0-9]';
Using {n,} or {n, m} string that specifies the number of consecutive occurrences of:
{N,}: n times represents at least match the previous character
{N, m}: indicates that the preceding character matches less than n times, not more than m times.
select * from test where name regexp 'x{2,}'; 或者 select * from test where name regexp 'x{2,4}';
5, the data insert, update, delete
1 "data is inserted:
insert into tb_name(column_list) values (value_list); 或者 insert into tb_name(column_list) values (value_list),(value_list),...; 或者 insert into tb_name values (value_list),(value_list),...; 或者 insert into tb_name(column_list) select (column_list) from tb_name2 where ...;
2 "to update the data:
update tb_name set column_name = value,... where ...;
3 "delete data:
delete from tb_name [where ...];
TRUNCATE the Table tb_name; // will delete the original table, and re-create a table