Escape single quote character for use in an SQLite query

Special characters and literal values in SQLite

Escaping quotes for SQL literals

In SQL statements, literal values enclosed within single quotes often contain ' characters. To keep SQLite from tripping, just double the quote:

INSERT INTO famous_quotes (quote) VALUES ('He said, ''Hello, World!''');
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It's like saying, "I'm quoting ''inside'' a quote." Inception, SQL-style!

BLOB literals and hexadecimal data

For hexadecimal data, SQLite has BLOB literals. A leading x or X followed by single-quoted hex data is the rule:

INSERT INTO table (blob_column) VALUES (X'536F6D65');
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The X says, "Here comes some hex!". It's like hex-data-superhero!

Handling NULL values

To insert a NULL value, just use the keyword without the quotes:

INSERT INTO table (column) VALUES (NULL);
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NULL, the ghost value. It's there but it's also not there. Balancing the Tao in SQL.

Securing and priming your SQLite queries

Preventing SQL injection

Double escaping quotes is a great step against SQL injection. Better yet, use parameterized queries:

-- Say NO to injection, yes to clean SQL. Safety first!
INSERT INTO users (username, password) VALUES (?, ?);
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Also, sanitize user input before constructing your SQL queries. SQL: "Cleanliness is next to godliness."

Handling DBNull and object conversion

With languages such as C# or Java, ensure DBNull values are correctly converted. Because NULL in SQL is like a hole in a donut - you don't see it, but it's still there!

Pre-processing in client languages

In Python or JavaScript, replace single quotes (') before building your SQL query:

# Python says, "Don't worry, I've got your back...slash."
safe_string = input_str.replace("'", "''")
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But remember, it's not a substitute for prepared statements. Like a cherry on top - nice, but not the cake!

Diverse scenarios and problems you may encounter

Correctly escaping within strings

Account for all places where single quotes might appear:

-- Using ' won't cut it:
SELECT * FROM books WHERE title = 'Children's Literature';

-- But '' will:
SELECT * FROM books WHERE title = 'Children''s Literature';
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Beware of non-standard escape sequences

Unlike other databases, SQLite doesn't play well with backslash \ escapes. So remember, backslashes are to SQLite what kryptonite is to Superman!

Pasting text into SQLite

When copying text into an SQLite query, beware of curly quotes. Only straight quotes get a pass:

-- Curly quotes, the unwanted guest:
INSERT INTO table (column) VALUES (‘Incorrect’);

-- Straight quotes, the preferred kind:
INSERT INTO table (column) VALUES ('Correct');
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Streamlining complex queries

For long or complex queries, use concatenated strings or text editors with SQL support to do the heavy lifting:

-- This is like a partition in partition match. Quotception!
SELECT * FROM authors WHERE bio LIKE '%''s%';
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