sql语句查询表中名字一样的资料(sql语句大全实例教程)

Introduction

SQL (Structured Query Language) is a programming language used to manage and manipulate databases. SQL was developed by IBM in 1970, and is now used by companies and organizations around the world. In this article, we will focus on how to query a table in SQL to find data with the same name.

Querying a table

To query a table in SQL, you will use the SELECT statement. The SELECT statement allows you to retrieve data from one or more tables. The basic syntax for the SELECT statement is as follows:

SELECT column1, column2, ... FROM table_name WHERE condition;

The WHERE clause is used to filter the results, and the condition specifies the criteria for the filter. To find data with the same name in a table, you will need to use the GROUP BY clause, which groups the results by a specified column. The syntax for the GROUP BY clause is as follows:

SELECT column1, COUNT(column1) FROM table_name GROUP BY column1 HAVING COUNT(column1) > 1;

This query will return all rows that have the same name in the specified column.

Conclusion

In conclusion, SQL is a powerful programming language used to manage and manipulate databases. To query a table in SQL to find data with the same name, you will need to use the SELECT statement with the GROUP BY clause. The GROUP BY clause allows you to group the results by a specified column, and the HAVING clause specifies the criteria for the filter. With these tools, you can easily find data with the same name in a table.