Register all PostgreSQL string functions
(conn: &Connection)
| 3 | |
| 4 | /// Register all PostgreSQL string functions |
| 5 | pub fn register_string_functions(conn: &Connection) -> Result<()> { |
| 6 | debug!("Registering string functions"); |
| 7 | |
| 8 | // Register split_part function |
| 9 | conn.create_scalar_function( |
| 10 | "split_part", |
| 11 | 3, |
| 12 | FunctionFlags::SQLITE_UTF8 | FunctionFlags::SQLITE_DETERMINISTIC, |
| 13 | |ctx| { |
| 14 | let string = ctx.get::<String>(0)?; |
| 15 | let delimiter = ctx.get::<String>(1)?; |
| 16 | let field_num = ctx.get::<i64>(2)?; |
| 17 | |
| 18 | if field_num < 1 { |
| 19 | return Ok("".to_string()); |
| 20 | } |
| 21 | |
| 22 | let parts: Vec<&str> = string.split(&delimiter).collect(); |
| 23 | let index = (field_num - 1) as usize; // Convert to 0-based index |
| 24 | |
| 25 | if index < parts.len() { |
| 26 | Ok(parts[index].to_string()) |
| 27 | } else { |
| 28 | Ok("".to_string()) |
| 29 | } |
| 30 | }, |
| 31 | )?; |
| 32 | |
| 33 | // Register string_agg function - this is an aggregate function |
| 34 | conn.create_aggregate_function( |
| 35 | "string_agg", |
| 36 | 2, |
| 37 | FunctionFlags::SQLITE_UTF8, |
| 38 | StringAggregator, |
| 39 | )?; |
| 40 | |
| 41 | // Register translate function |
| 42 | conn.create_scalar_function( |
| 43 | "translate", |
| 44 | 3, |
| 45 | FunctionFlags::SQLITE_UTF8 | FunctionFlags::SQLITE_DETERMINISTIC, |
| 46 | |ctx| { |
| 47 | let string = ctx.get::<String>(0)?; |
| 48 | let from_chars = ctx.get::<String>(1)?; |
| 49 | let to_chars = ctx.get::<String>(2)?; |
| 50 | |
| 51 | let from_vec: Vec<char> = from_chars.chars().collect(); |
| 52 | let to_vec: Vec<char> = to_chars.chars().collect(); |
| 53 | |
| 54 | let mut result = String::new(); |
| 55 | for ch in string.chars() { |
| 56 | if let Some(pos) = from_vec.iter().position(|&c| c == ch) { |
| 57 | if pos < to_vec.len() { |
| 58 | result.push(to_vec[pos]); |
| 59 | } |
| 60 | // If to_chars is shorter than from_chars, characters are removed |
| 61 | } else { |
| 62 | result.push(ch); |