How to find a character in a string and replace it?

[jameszow]

This is my sentence. I want to find each item and replace it：

UPDATE nucleic_test_institution SET institution_name = ? institution_address = ？WHERE id = ?

institution_name = ? and institution_address = ？ replace institution_name = ?, and institution_address = ？

fn update_nucleic_institution(&self) -> bool {
        let mut add_symbols: Vec<String> = Vec::new();

        let mut sql_stmt = String::from("UPDATE nucleic_test_institution SET ");
        let mut coon = dbconfig::get_conn().unwrap();

        let data = self.into();

        match data {
            Some(data) => {
                match &data.institution_name {
                    Some(_institution_name) => {
                        sql_stmt.push_str("institution_name = ? ");
                        add_symbols.push(String::from("institution_name = ? "));
                    }
                    None => (),
                }
                match &data.institution_address {
                    Some(_institution_address) => {
                        sql_stmt.push_str("institution_address = ? ");
                        add_symbols.push(String::from("institution_address = ? "));
                    },
                    None => (),
                }
                match &data.institution_phone {
                    Some(_institution_phone) => {
                        sql_stmt.push_str("institution_phone = ? ");
                        add_symbols.push(String::from("institution_phone = ? "));
                    },
                    None => (),
                }
                match &data.institution_region {
                    Some(_institution_region) => {
                        sql_stmt.push_str("institution_region = ? ");
                        add_symbols.push(String::from("institution_region = ? "));
                    },
                    None => (),
                }
            }
            None => (),
        }
        sql_stmt.push_str(" WHERE id = ?");

        if add_symbols.len() > 1 {
            for item in add_symbols {

                let str = &item;
                let new_str = str.to_owned() + ",";

                println!("{}", new_str);

                // if sql_stmt.contains(&item) {
                //     sql_stmt.find(pat: P)
                // }
            }
        }
        println!("sql: {}", sql_stmt);

        let result = coon.exec_drop("UPDATE nucleic_test_institution SET institution_name = ?, institution_address = ?, institution_phone = ?, institution_region = ?
                                WHERE id = ?", 
                        (&self.institution_name, &self.institution_address, &self.institution_phone, &self.institution_region, &self.id));

        if result.is_ok(){
            return true;
        } 
        false
    }

I see find method will only return its Unicode value

[jjpe]

From your code or seems to me that what you're looking for is something like the prepared statement feature offered by eg sqlx.

[jameszow]

yes, i'm writing an SQL parsing. I want to know how to remove the last element of the string array

[jameszow]

     let mut add_symbols: Vec<String> = Vec::new();
     add_symbols.push(String::from("institution_name = ? "));
     add_symbols.push(String::from("institution_address = ? "));

        if add_symbols.len() > 1 {
            for mut item in add_symbols {
                item.push_str(",");
                sql_stmt.push_str(&item);
            }
        }

I want to remove institution_address = ?

[jameszow]

have already been solved