Mysql returns all table names of a database, column name data type notes _mysql

DESC table name;
Show columns from table name;
describe table name;
Show create table name;

Use Information_schema
SELECT * from columns where table_name= ' table name ';


By the way, note:
show databases;
I can do that.

Use Information_schema

Select Table_schema,table_name from tables where table_schema= ' database name '

Use database name;
Show tables;
The original unique index Ak_pas_name (pac_name) is in table Tb_webparamcounter,
Execute the following SQL modification index
ALTER TABLE Tb_webparamcounter DROP INDEX ak_pas_name;
ALTER TABLE Tb_webparamcounter add UNIQUE ak_pas_name (pc_id,pac_name);


If you find that the logic of the index is incorrect, you need to add another field to go in and execute
ALTER TABLE Tb_webparamcounter DROP INDEX ak_pas_name;
ALTER TABLE Tb_webparamcounter add UNIQUE ak_pas_name (pc_id,pac_name,pac_value);
Note: At this time the Pc_id,pac_name,pac_value three fields are not foreign KEY
Otherwise, you must drop FOREIGN KEY first, and then redo the previous step.


Get Column name data type note
SELECT column_name, Data_type, column_comment from information_schema.columns WHERE table_name =?