MySQL use of SQL statements-170413

1. Insert several fields from table T2 into table T1:

INSERT INTO T1 (t1.c1,..., t1.c5) Select T2.c1,..., t2.c5 from T2;

The time function in 2.MySQL:

Curdate () 2017-04-13

Now () 2017-04-13 09:09:09

3. Replace:

UpdateName of the tableSetthe name of the field to replace for this table=replace (the name of the field to replace for this table, 'Original Content', 'New Content')

4. Intercept the string:

SUBSTR (field name, nth bit start intercept, intercept m bit)

5. Delete:

Delete Records in table: Delete from table tablename where condition ... ；

Delete tables: drop TABLE tablename;

6. Positioning:

LOCATE (string, field name)--locates the position of the string in the data;

7. Find table 1, table 2, field 1 is the same, field 2 different data;

SELECT t1.* from person_lnfo T1 joins Person_lnfo T2 on T1.houseid=t2.houseid and t1.unitid<>t2. Unitid;

MySQL use of SQL statements-170413