Concatenating Text and Values in Go SQL Queries

When constructing a text SQL query in Go, there are certain syntax rules to follow when concatenating string and value components, particularly when using integers.

In the Python code provided, the tuple approach is not valid in Go, and attempting to cast parameters as strings will result in type mismatch errors.

The idiomatic way to accomplish this in Go is to use fmt.Sprintf to format the query string. This allows you to embed values within the string at runtime:

query := fmt.Sprintf(`SELECT columnA FROM tableA WHERE columnB = %d AND columnB = %s`,
                     someNumber, someString)

Here, the placeholders %d and %s represent integer and string values, respectively, which are then assigned during the db.Query call:

rows, err := db.Query(query, val1, val2)

This approach ensures that the values are correctly formatted and prevents SQL injection vulnerabilities.

Avoiding SQL Injection

It is crucial to note that string concatenation in SQL queries can lead to injection vulnerabilities. To mitigate this risk, use prepared statements and parameterized queries. By passing values as parameters, you can prevent malicious input from modifying the intended SQL query.

For example:

stmt, err := db.Prepare(`SELECT columnA FROM tableA WHERE columnB = ? AND columnB = ?`)
rows, err := stmt.Query(val1, val2)

By using prepared statements, you can safeguard your application from malicious SQL input while maintaining the convenience of constructing dynamic queries.