Check whether a table exists in the MySQL database in C.

Placeholder first, edit later

There are four ways to judge:

1. Show tables like 'testtable ';

This method is not easy to implement in the code.
2. SelectTABLE_NAMEFromINFORMATION_SCHEMA.TABLESWhereTABLE_SCHEMA= 'Dbname'
AndTABLE_NAME= 'Tablename'
;

This method is easy to implement. An instance that determines whether the testtable table exists in mybase:

MySQL; mysql_res * result = NULL; int COUNT = 0; If (0 = mysql_query (& MySQL, "select table_name from information_schema.tables where table_schema = 'mybase' and table_name = 'testtable'") {result = mysql_store_result (& MySQL); Count = mysql_num_rows (result );} else {printf ("error: % s \ n", mysql_error (& MySQL);} If (count> 0) printf ("This table already exists ");

3. Call mysql_list_tables (MySQL * MySQL, "tablename.

It is still used to determine whether there is a testtable instance in the mybase database currently connected:

MYSQL_RES *result=mysql_list_tables(&mysql,"testtable");MYSQL_ROW row;int count = 0;while((row=mysql_fetch_row(result))!=NULL){printf("TABLE %d: %s\n",cnt,row[0]);  cnt++;}if (mysql_errno(&mysql))  //mysql_fetch_row() failed due to an error{fprintf(stderr, "Error:%s\n",mysql_error(&mysql));}

If (count> 0) printf ("This table already exists ");

4. If the table does not exist, you can use the create table if not exists tablename command to create the table without querying whether the table exists.

You can also use APIs such as mysql_query.