Using MySQL, you can create databases of various topics and sizes, from small collections of tables to huge corporate databases. Large databases are much more difficult to maintain than small databases due to the variety of tables and the relationships between them. It is often necessary to check whether a table has been created earlier or not.
Necessary
knowledge of MySQL
Instructions
Step 1
The administrator communicates with the database using special requests. Queries are formed in the MySQL language with a special programming language that has its own writing rules and a set of operators. As a rule, to check the existence of a table, you need to enter certain queries that check the base and give you an accurate result. Try to enter such combinations correctly, as if misused, you can make various errors on the server.
Step 2
To check the existence of a table by a given name, use a query of the form:
SELECT TABLE_NAME FROM INFORMATION_SCHEMA. TABLES WHERE TABLE_SCHEMA = 'dbname' AND TABLE_NAME = 'tablename'
The dbname and tablename values should be replaced with your names. If you need to create a table later, if one was not found, use a command of the form:
CREATE TABLE IF NOT EXISTS
Step 3
If communication with the database is carried out through msysobjects, then the request for the presence of a specific table should look like:
SELECT COUNT (*) FROM msysobjects WHERE type = 1 AND name = 'tablename'
If you need to delete a table, if it is found, then write a query as follows:
DROP TABLE IF EXISTS table;
Step 4
Modern MySQL-based databases can have tens of thousands of tables with millions of rows. It can be difficult to understand such a jumble of information. However, there are special requests to solve such problems. In general, we can say that checking the existence of a table takes a lot of time and effort. To make it easier for you to work with tables in the future, learn special tutorials on the MySQL programming language, since it is completely related to tables and allows you to perform various operations.
