How to query how many columns in oracle

In Oracle, you can use the select statement with "count(*)" to query how many columns there are in the table. The syntax is "select count(*) from user_tab_cols where table_name='table name'"; "user_tab_cols" It can also be used to query hidden columns, and the English in the table name should use uppercase letters.

The operating environment of this tutorial: Windows 10 system, Oracle version 12c, Dell G3 computer.

How to query how many columns in oracle

How many columns to query in oracle:

select count(*) from user_tab_cols where table_name='表名';

--If the table name contains English, it should be English capital letters

Examples are as follows:

Extended knowledge:

The difference between user_tab_cols and user_tab_columns in Oracle

Both tables can be used to query Table, View and Clusters under the user

Difference

-- 通过执行此SQL语句，可发现user_tab_cols还包含隐藏列，因此平时使用时推荐使用user_tab_columns
select column_name from user_tab_cols where table_name = 'TEST'
minus
select column_name from user_tab_columns where table_name = 'TEST';

By comparing with user_tab_comments (table comments), user_col_comments ( Field comments) can basically meet general statistical needs.

How many columns can be queried by mysql:

select count(*) from information_schema.COLUMNS where table_name='表名';

--The table name can be both uppercase and lowercase

How many columns can be queried by sqlserver:

select count(*) from syscolumns s  where s.id = object_id('test');

--Table names can be uppercase or lowercase

Recommended tutorial: "Oracle Video Tutorial"

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