How does Oracle determine whether a table exists?

The "SELECT COUNT(*) FROM ALL_TABLES WHERE OWNER=UPPER('user name') AND TABLE_NAME=UPPER('table name')" statement can be used in oracle to determine whether the specified table exists. If it returns "0 ” then the table does not exist.

The operating environment of this tutorial: Windows 7 system, Oracle 11g version, Dell G3 computer.

Oracle database determines whether a table exists

1. The first sql

select count(*) from user_tables where table_name =upper('表名')

This is to query the currently logged in user Whether the table exists in all tables in . Note that the table name is case-sensitive. If the parameters are not restricted, then the upper function must be added here.

The effect is as follows:

2. The second sql

SELECT COUNT(*) FROM ALL_TABLES WHERE OWNER = UPPER('用户名') 
AND TABLE_NAME = UPPER('表名')

Example:

Queryznxd_1 Whether the table exists in the table under this user. For example, if you log in as user znxd_gateway, and execute the above sql on its query panel, you can query whether a certain table exists under this user znxd_1.

The effect is as follows:

That is to say, when 0 is returned, it means that the database does not have the table, and 1# is returned ## indicates that the table exists.

Recommended tutorial: "

Oracle Tutorial"

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