postgres-parser 0.2.3

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    Copyright (c) 2020, ZomboDB, LLC

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*/
use postgres_parser::*;

/// A simple CLI example that parses the entire file specified by the first argument.
///
/// This example uses the `SqlStatementScanner` to scan the file and parse each full SQL
/// statement, one at a time.
///
/// It outputs each original SQL statement and its corresponding JSON representation.  If the
/// statement was a "COPY ... FROM stdin;" statement, then the subsequent data payload is
/// also output.
///
/// ## Usage
///
/// ```shell
/// $ target/debug/examples/scanner /path/to/schema.sql
/// ```
fn main() {
    let args: Vec<String> = std::env::args().collect();
    let filename = args.get(1).expect("no filename");
    let contents =
        std::fs::read_to_string(filename).expect(&format!("failed to read file: {}", filename));

    // the scanner is essentially an iterator that iterates over each complete SQL statement
    // in its input.  Here we construct a new SqlStatementScanner and iterate over the results
    let scanner = SqlStatementScanner::new(&contents);
    for (i, stmt) in scanner.into_iter().enumerate() {
        // output the raw SQL string from the scanner
        println!("#{}\n{}", i + 1, stmt.sql.trim_end());

        // and now we look at what it parsed
        match stmt.parsetree {
            // it was able, via Postgres' parser, to successfully parse the statement
            // output it as json
            Ok(parsetree) => {
                let as_json = serde_json::to_string(&parsetree).expect("failed to convert to json");
                println!("-- {}", as_json);

                // output corresponding payload data (likely COPY ... FROM stdin; data)
                if stmt.payload.is_some() {
                    println!("/* DATA:\n{}\n*/", stmt.payload.unwrap());
                }
            }

            // it couldn't be parsed.  Just display the underlying parse error
            Err(e) => {
                println!("-- ERROR:  {:?}", e);
            }
        };
        println!();
    }
}