Can mysql read csv files

MySQL cannot read CSV files directly. It can be implemented indirectly by using the LOAD DATA INFILE statement: fast, efficient, but strict requirements on CSV format. Using programming languages ​​(such as Python): High flexibility, can handle complex formats, but slower.

Can MySQL read CSV files? The answer is: it cannot be read directly, but it can be implemented indirectly through some methods. This cannot be summarized by a simple sentence "can" or "can't", there are many ways to do it. It is impossible to solve the problem by directly using MySQL's built-in functions. It's like trying to screw nails with a screwdriver. If the tool is wrong, it will be useless no matter how hard it is.

Let's first talk about why MySQL cannot read CSV directly. MySQL is essentially a relational database management system that is good at handling structured data, while CSV files are text files with relatively loose structure. The original intention of MySQL is to revolve around the structured concepts of tables, rows, and columns. It did not expect that one day it would directly chew on such "non-standardized" text.

So how can I import CSV data into MySQL? There are many methods, each with its advantages and disadvantages, so I will explain it in detail to you.

The most commonly used method and the most recommended method are to use LOAD DATA INFILE statement. This is MySQL's killer weapon, specially used to import data from text files. It is fast, efficient, and relatively simple and easy to use.

Let’s take a look at an example. Suppose your CSV file is named data.csv , located in the /tmp directory, and contains three columns of data: id , name , age , and the first line of the file is the header.

 <code class="sql">LOAD DATA INFILE '/tmp/data.csv' INTO TABLE my_table FIELDS TERMINATED BY ',' ENCLOSED BY '"' LINES TERMINATED BY '\n' IGNORE 1 LINES;</code>

The core of this code is LOAD DATA INFILE , followed by the file path. FIELDS TERMINATED BY ',' Specify the field separator as a comma, ENCLOSED BY '"' Specify the field value is surrounded by double quotes (which depends on your CSV file format), LINES TERMINATED BY '\n' the line separator as a newline, IGNORE 1 LINES ignores the first line header. Note that the file path, field separator, quotes, etc. must be adjusted according to your actual CSV file. This is a place where errors are prone to errors, and a little carelessness will cause the import to fail. If your CSV file encoding is not UTF-8, you also need to specify CHARACTER SET parameter.

The advantage of this method is that it is high efficiency, direct operation of the underlying layer, and rapid speed. But the disadvantages are also obvious. It has strict requirements on the format of CSV files, and a slight deviation may lead to the import failure. Moreover, you have to make sure that the MySQL server has permission to read the /tmp/data.csv file, otherwise an error will be reported. Many novices will suffer from permission issues and must check them in advance.

Another way is to use some programming language, such as Python. Python's csv module can easily read CSV files and then use Python's database to connect to the library, such as mysql.connector , to insert data into MySQL tables. The advantage of this approach is its high flexibility, can handle a variety of complex CSV file formats, and can even perform data cleaning and conversion. But the disadvantage is that the speed is relatively slow, because it needs to be processed in the middle of the programming language.

Let's give a simple Python example:

 <code class="python">import csv import mysql.connector mydb = mysql.connector.connect( host="localhost", user="yourusername", password="yourpassword", database="mydatabase" ) mycursor = mydb.cursor() with open('/tmp/data.csv', 'r') as file: reader = csv.reader(file) next(reader) # skip header row for row in reader: sql = "INSERT INTO my_table (id, name, age) VALUES (%s, %s, %s)" val = (row[0], row[1], row[2]) mycursor.execute(sql, val) mydb.commit() print(mycursor.rowcount, "record inserted.")</code>

Remember to replace yourusername , yourpassword , mydatabase and my_table as your actual values. This method requires the installation of mysql.connector library: pip install mysql-connector-python

The two methods have their own advantages, and which method to choose depends on your specific needs and environment. If your CSV file is small and the format is relatively standardized, then LOAD DATA INFILE is the best choice. If your CSV file is large, has a complex format, or needs data cleaning and conversion, it will be more flexible to use Python or other programming languages. Remember, no matter which method you choose, carefully check your CSV file format to ensure the data type matches and avoid unnecessary errors. Test in advance and avoid detours.

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