One article teaches you how to use SQL parsing in Python using SQLparse

1. Background

During development, you often encounter various problems when processing SQL statements, such as formatting SQL, analyzing SQL structures, etc. Handling these tasks manually is not only tedious, but also prone to errors. The sqlparse library can help us parse and process SQL statements efficiently. It provides powerful SQL parsing functions and can easily implement SQL formatting, word segmentation, syntax analysis and other operations. Next, let's dive into this powerful tool.

2. What is sqlparse

sqlparse is a Python third-party library designed for parsing and formatting SQL statements. It can decompose SQL statements into multiple syntax units, which facilitates us to perform further processing and analysis.

3. How to install sqlparse

As a third-party library, you can install sqlparse through the following command line:

pip install sqlparse

Once the installation is complete, you can import and use it in your Python program.

4. How to use library functions

The following are several commonly used functions of sqlparse and their usage methods:

1. (sql)

Used to parse SQL statements, returning a parsed object list.

import sqlparse

sql = "SELECT * FROM my_table WHERE id = 1"
parsed = (sql)
print(parsed)

(sql): parses SQL statements and returns the parsed object.

2. (sql, reindent=True, keyword_case='upper')

Used to format SQL statements, support reindentation and keyword case conversion.

import sqlparse

sql = "select * from my_table where id = 1"
formatted_sql = (sql, reindent=True, keyword_case='upper')
print(formatted_sql)

(sql, reindent=True, keyword_case='upper'): Format SQL, reindent=True means reindent, keyword_case='upper' means converting keyword to uppercase.

3. (sql)

Used to split multiple SQL statements into separate statements.

import sqlparse

sql = "SELECT * FROM my_table; INSERT INTO my_table VALUES (1, 'test')"
statements = (sql)
print(statements)

(sql): Split multiple SQL statements into separate statements.

4.

Used to get the participle result of SQL statements.

import sqlparse

sql = "SELECT * FROM my_table WHERE id = 1"
parsed = (sql)[0]
tokens = 
print(tokens)

(sql)[0].tokens: Get the word participle result of SQL statement.

5.

Used to process identifiers in SQL.

import sqlparse

sql = "SELECT my_column FROM my_table"
parsed = (sql)[0]
for token in :
    if isinstance(token, ):
        print(token)

: Used to process identifiers in SQL.

5. Use scenarios

The following are examples of sqlparse application in different scenarios:

1. Format SQL statements

import sqlparse

sql = "select * from my_table where id = 1"
formatted_sql = (sql, reindent=True, keyword_case='upper')
print(formatted_sql)

(sql, reindent=True, keyword_case='upper'): Format SQL statements into standard formats for easy reading.

2. Analyze SQL structure

import sqlparse

sql = "SELECT * FROM my_table WHERE id = 1"
parsed = (sql)[0]
for token in :
    if  is :
        print()

(sql)[0].tokens: After parsing the SQL statement, keywords can be extracted by traversing the word participle results.

3. Handle placeholders

import sqlparse

sql = "SELECT * FROM my_table WHERE id = ?"
parsed = (sql)[0]
for token in :
    if  is :
        print()

: Identify placeholders in SQL statements.

4. Split multiple SQL statements

import sqlparse

sql = "SELECT * FROM my_table; INSERT INTO my_table VALUES (1, 'test')"
statements = (sql)
for statement in statements:
    print(statement)

(sql): Split multiple SQL statements into separate statements for easy processing one by one.

5. Extract table names

import sqlparse

sql = "SELECT * FROM my_table"
parsed = (sql)[0]
for token in :
    if isinstance(token, ):
        print(token.get_real_name())

.get_real_name(): Extract SQL

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