Sqlite - replace part of a string

A few useful strategies

Back up first

Imagine you just typed an UPDATE command that changed every name in your database to "Bob". Accidents happen. Always back up before you execute.

Test query before execution

Perform a dry run using the SELECT command, just like checking your parachute before you jump:

SELECT REPLACE(column_name, 'old_text', 'new_text') FROM table_name WHERE column_name LIKE '%old_text%';
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This will provide a proof of consequences without the commitment.

Limit use of WHERE clause

If 'old_text' is a party crasher who invited himself everywhere, and you need to replace every occurrence across multiple rows, remove the WHERE clause:

UPDATE table_name
SET column_name = REPLACE(column_name, 'old_text', 'new_text');
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Escape characters handling

Working with file paths in SQLite is like diffusing a bomb, one wrong wire and it's all over. Use double backslashes (\\) to avoid the blast:

UPDATE table_name
SET column_name = REPLACE(column_name, 'C:\\old_directory', 'D:\\new_directory');
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Complex cases and how to handle them

Case sensitivity matters

The REPLACE() function takes case sensitivity as seriously as an English professor. The term "Bob" is not the same as "bob". For case-insensitive operations, you might need something beyond standard SQL.

Dealing with advanced regex patterns

SQLite can play the REGEXP game, but you need to compile it with the REGEXP extension first. This comes in handy when you have sophisticated patterns to deal with.

Advanced usage - When standard tools aren't enough

Creating custom functions for an enhanced toolset

When your string operations become as complex as chess, you can define your own functions (UDFs) using SQLite's API for more complex string operations.

Inclusion of other string functions

SQLite has an armory of string manipulation tools. You can use methods like SUBSTR() or INSTR() in concert with REPLACE() to conduct a full-scale text transformation.

Layering operations

Use multiple functions in a single query, like removing a nuisance of a substring while also replacing another:

UPDATE table_name
SET column_name = REPLACE(SUBSTR(column_name, INSTR(column_name, 'start')), 'old_text', 'new_text');
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