rust sqlx访问时ColumnNotFound错误

[Arteez-gif]

rust版本：rustc 1.90.0 (1159e78c4 2025-09-14
sqlx版本：v0.8.0

let db_url = "mysql://xxx:xxx@host:port?ssl-mode=disabled";
let conn_options = MySqlConnectOptions::from_str(db_url)?
.disable_statement_logging()
.no_engine_subsitution(false)
.pipes_as_concat(false)
.timezone(None)
.charset("utf8mb4")
.collation("utf8mb4_unicode_ci")
.set_names(false);

let sql: &'static str = "SELECT * from xxx.xx";
let mut rows = sqlx::query(sql)
.fetch_all(&conn_pool).await?;

for row in &rows {
let col_name: &'static str = "TEST_COLUMN";
let test_column: String = row.try_get(col_name)?;
println!("{}", test_column);
}
连接gaea执行这种普通的SQL语句，会报错Error: ColumnNotFound('TEST_COLUMN')。

1. 但是直接连接mysql节点执行没有问题。
2. 将let test_column: String = row.try_get(col_name)?;
   改为let test_column: String = row.try_get(0)try_get参数中使用正确的列索引也能正确执行。

[github-actions]

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[gongna-au]

@Arteez-gif Please wait, I'll try to reproduce the issue on my end.

[gongna-au]

@Arteez-gif hi I successfully reproduced this problem. This feature has been fixed in the C++ implementation, but this functionality cannot be extended to all versions for two reasons: 1. Gaea needs to query columns from the actual MySQL database, increasing network overhead; 2. It is difficult to support this feature in sharded database scenarios.

复现步骤

正常场景

use sqlx::{Column, Row, TypeInfo};
use sqlx::mysql::MySqlConnectOptions;
use std::str::FromStr;

async fn inspect_metadata(label: &str, url: &str) -> Result<(), sqlx::Error> {
    println!("\n--- Testing Metadata for: {} ---", label);
    
    let pool = sqlx::MySqlPool::connect(url).await?;
    let sql = "SELECT * FROM db.demo LIMIT 1";
    let row = sqlx::query(sql).fetch_one(&pool).await?;

    // 关键证明点：打印数据库返回的原始列名
    for col in row.columns() {
        let actual_name = col.name();
        println!("  Column name in Metadata: '{}'", actual_name);
        
        // 尝试匹配代码中的大写常量
        let target = "TEST_COLUMN";
        if actual_name == target {
            println!("  ✅ MATCH SUCCESS: Found '{}'", target);
        } else {
            println!("  ❌ MATCH FAILED: Found '{}' but expected '{}'", actual_name, target);
        }
    }
    Ok(())
}

#[tokio::main]
async fn main() {
    let gaea_url = "mysql://superroot:superroot@127.0.0.1:13306/db";
    let mysql_url = "mysql://superroot:superroot@127.0.0.1:3379/db";

    if let Err(e) = inspect_metadata("Gaea Proxy", gaea_url).await {
        println!("Gaea Error: {:?}", e);
    }

    if let Err(e) = inspect_metadata("Direct MySQL", mysql_url).await {
        println!("MySQL Error: {:?}", e);
    }
}

--- Testing Metadata for: Gaea Proxy ---
  Column name in Metadata: 'TEST_COLUMN'
  ✅ MATCH SUCCESS: Found 'TEST_COLUMN'

--- Testing Metadata for: Direct MySQL ---
  Column name in Metadata: 'TEST_COLUMN'
  ✅ MATCH SUCCESS: Found 'TEST_COLUMN'

报错场景

use sqlx::{Column, Row, ConnectOptions}; // 必须加上 ConnectOptions
use sqlx::mysql::MySqlConnectOptions;
use std::str::FromStr;

async fn inspect_metadata(label: &str, url: &str) -> Result<(), sqlx::Error> {
    println!("\n--- Testing Metadata for: {} ---", label);
    
    let opts = MySqlConnectOptions::from_str(url)?
        .statement_cache_capacity(10) // 业务复现：必须设置大于 0 才会触发缓存逻辑
        .disable_statement_logging();

    let pool = sqlx::MySqlPool::connect_with(opts).await?;
    
    // 业务场景复现：
    // 第一次执行，sqlx 会发 PREPARE。如果 Gaea 返回了错误的元数据，
    // sqlx 会把这个错误的映射关系存入缓存。
    let sql = "SELECT * FROM db.demo LIMIT 1";
    let row = sqlx::query(sql).fetch_one(&pool).await?;

    for col in row.columns() {
        println!("  Real column in metadata: '{}'", col.name());
        
        let target = "TEST_COLUMN";
        // 尝试模拟业务报错：
        match row.try_get::<String, &str>(target) {
            Ok(_) => println!("  ✅ Success matching '{}'", target),
            Err(e) => println!("  ❌ FAILURE: {:?} (This replicates your production bug!)", e),
        }
    }
    Ok(())
}

#[tokio::main]
async fn main() {
    let gaea_url = "mysql://superroot:superroot@127.0.0.1:13306/db";
    let mysql_url = "mysql://superroot:superroot@127.0.0.1:3379/db";

    let _ = inspect_metadata("Gaea Proxy", gaea_url).await;
    let _ = inspect_metadata("Direct MySQL", mysql_url).await;
}

--- Testing Metadata for: Gaea Proxy ---
  Real column in metadata: 'TEST_COLUMN'
  ❌ FAILURE: ColumnNotFound("TEST_COLUMN") (This replicates your production bug!)

--- Testing Metadata for: Direct MySQL ---
  Real column in metadata: 'TEST_COLUMN'
  ✅ Success matching 'TEST_COLUMN'

复现结论

root cause：Gaea Prepare did not return the actual column names.The frameworks currently found to have this problem are Rust and C++.