如何使用phpmyadmin在沒有主鍵的情況下找到桌子？

要找出phpMyAdmin中未設置主鍵的表，可使用數據庫模式視圖或運行自定義SQL查詢。 1.點擊“Designer”或“Schema”標籤頁查看表關係，通過視覺判斷哪些表未連接；2.運行指定SQL語句：SELECT TABLE_NAME FROM information_schema.TABLES WHERE TABLE_SCHEMA = 'your_database_name' AND TABLE_NAME NOT IN (SELECT DISTINCT TABLE_NAME FROM information_schema.KEY_COLUMN_USAGE WHERE CONSTRAINT_NAME = 'PRIMARY')，替換數據庫名後執行，返回無主鍵的表；3.確認缺失後，通過“Structure”標籤頁添加唯一標識列或組合列作為主鍵。無主鍵可能影響數據庫性能與數據完整性，應及時修復。

If you're managing a MySQL database through phpMyAdmin and want to find tables that don't have a primary key, there's a straightforward way to do it without writing complex queries from scratch. The trick involves checking the database schema or using SQL queries inside phpMyAdmin to spot tables missing primary keys.

Check the Schema View

One of the easiest ways to get an overview is by using phpMyAdmin's built-in schema view:

• Go to your database in phpMyAdmin.
• Click on the "Designer" tab at the top.
• In some versions, you'll see a "Schema" tab instead — click that.
• This will show a visual layout of your tables and their relationships.

While this doesn't explicitly highlight missing primary keys, you can visually scan each table. A properly connected schema usually relies on primary and foreign keys, so tables floating alone or not connecting properly might be missing a primary key.

Run a Custom SQL Query

For a more direct and accurate method, use a query that checks the information_schema database. Here's one you can run directly in the SQL tab of phpMyAdmin:

 SELECT TABLE_NAME
FROM information_schema.TABLES
WHERE TABLE_SCHEMA = 'your_database_name'
  AND TABLE_NAME NOT IN (
    SELECT DISTINCT TABLE_NAME
    FROM information_schema.KEY_COLUMN_USAGE
    WHERE CONSTRAINT_NAME = 'PRIMARY'
      AND TABLE_SCHEMA = 'your_database_name'
  );

Replace 'your_database_name' with the actual name of your database.

This query:

• Selects all tables in your database.
• Filters out those that have a primary key defined.
• Returns only the tables without a primary key.

You can copy and paste this into the SQL window in phpMyAdmin and hit "Go" — it'll list all tables missing a primary key.

Why It Matters and What to Do Next

Tables without a primary key can cause issues down the line, especially if you're using replication, trying to optimize queries, or building relationships between tables. If you find tables missing primary keys:

• Review the data structure: Is there a column (or set of columns) that uniquely identifies each row?
• Consider adding an auto-incrementing ID column as a primary key if none exists.
• Use the Structure tab in phpMyAdmin to modify the table and define a primary key.

For example:

• Open the table in phpMyAdmin.
• Click the Structure tab.
• Select one or more columns and click "Primary" under the "Action" column.
• Or add a new column like id INT AUTO_INCREMENT PRIMARY KEY .

Finding tables without a primary key in phpMyAdmin isn't something the UI does automatically, but with a quick query or visual inspection, it's easy enough to track them down. Once identified, fixing them is often just a matter of defining the right field or combination of fields as the primary key.

基本上就這些。

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