Lindorm:Use ODBC para desenvolver aplicações

Etapa 1: Instale o driver ODBC para MySQL

Baixe e instale o driver ODBC para MySQL no site oficial do MySQL.

Etapa 2: Instale o unixODBC

Instale o unixODBC no Linux:

yum install unixODBC-devel

Etapa 3: Configure o driver no arquivo odbcinst.ini

Adicione a seguinte entrada ao arquivo odbcinst.ini.

[MySQL]
Description	= ODBC for MySQL
Driver		= /usr/lib/libmyodbc8a.so
Setup		= /usr/lib/libmyodbc8w.so
Driver64	= /usr/lib64/libmyodbc8a.so
Setup64		= /usr/lib64/libmyodbc8w.so
FileUsage	= 1

Etapa 4: Conecte-se ao LindormTable no código

Use SQLDriverConnect para estabelecer a conexão. O formato da string de conexão é:

DRIVER={MySQL};SERVER=<endpoint>;PORT=33060;DATABASE=<database>;USER=<username>;PASSWORD=<password>

Como escolher o endpoint correto para SERVER:

• Instância ECS (VPC): Use o LindormTable VPC endpoint for MySQL para garantir menor latência e maior segurança.

• Servidor local (Internet): Ative o endpoint público no console do Lindorm. Acesse Database Connections > Wide Table Engine e clique em Enable Public Endpoint na aba Wide Table Engine. Em seguida, utilize o LindormTable Internet endpoint for MySQL.

Etapa 5: Execute consultas

Após conectar-se com sucesso, aloque um identificador de instrução e execute SQL com SQLExecDirect. O exemplo abaixo executa show databases e imprime cada linha do resultado:

if (ret == SQL_SUCCESS || ret == SQL_SUCCESS_WITH_INFO) {
    printf("Connection established. \n");

    // Perform the query.
    SQLAllocHandle(SQL_HANDLE_STMT, dbc, &stmt);
    SQLExecDirect(stmt, (SQLCHAR*)"show databases", SQL_NTS);

    // Obtain query results.
    SQLCHAR result[50];
    while (SQLFetch(stmt) == SQL_SUCCESS) {
        SQLGetData(stmt, 1, SQL_C_CHAR, result, sizeof(result), NULL);
        printf("database: %s\n", result);
    }

    // Release resources.
    SQLFreeHandle(SQL_HANDLE_STMT, stmt);
    SQLDisconnect(dbc);
} else {
    SQLCHAR sqlState[6];
    SQLCHAR msg[SQL_MAX_MESSAGE_LENGTH];
    SQLINTEGER nativeError;
    SQLSMALLINT actualMsgLen;

    SQLGetDiagRec(SQL_HANDLE_DBC, dbc, 1, sqlState, &nativeError, msg, sizeof(msg), &actualMsgLen);
    printf("Connection failed: %s\n", msg);
}

// Release resources.
SQLFreeHandle(SQL_HANDLE_DBC, dbc);
SQLFreeHandle(SQL_HANDLE_ENV, env);

return 0;

#include <stdio.h>
#include <stdlib.h>
#include <sql.h>
#include <sqlext.h>

int main() {
    // Define connection handles.
    SQLHENV env;
    SQLHDBC dbc;
    SQLHSTMT stmt;
    SQLRETURN ret;

    // Initialize the ODBC environment.
    SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &env);
    SQLSetEnvAttr(env, SQL_ATTR_ODBC_VERSION, (SQLPOINTER)SQL_OV_ODBC3, SQL_IS_INTEGER);

    // Allocate a connection handle and set the login timeout.
    SQLAllocHandle(SQL_HANDLE_DBC, env, &dbc);
    SQLSetConnectAttr(dbc, SQL_LOGIN_TIMEOUT, (SQLPOINTER)5, SQL_IS_INTEGER);

    // Connect to LindormTable.
    // Replace the SERVER, DATABASE, USER, and PASSWORD values with your own.
    ret = SQLDriverConnect(dbc, NULL, (SQLCHAR*)"DRIVER={MySQL};SERVER=ld-uf6k8yqb741t3****-proxy-sql-lindorm-public.lindorm.rds.aliyuncs.com;PORT=33060;DATABASE=default;USER=user;PASSWORD=test", SQL_NTS, NULL, 0, NULL, SQL_DRIVER_COMPLETE);

    if (ret == SQL_SUCCESS || ret == SQL_SUCCESS_WITH_INFO) {
        printf("Connection established. \n");

        // Run a query.
        SQLAllocHandle(SQL_HANDLE_STMT, dbc, &stmt);
        SQLExecDirect(stmt, (SQLCHAR*)"show databases", SQL_NTS);

        // Print each row.
        SQLCHAR result[50];
        while (SQLFetch(stmt) == SQL_SUCCESS) {
            SQLGetData(stmt, 1, SQL_C_CHAR, result, sizeof(result), NULL);
            printf("database: %s\n", result);
        }

        // Release statement resources.
        SQLFreeHandle(SQL_HANDLE_STMT, stmt);
        SQLDisconnect(dbc);
    } else {
        SQLCHAR sqlState[6];
        SQLCHAR msg[SQL_MAX_MESSAGE_LENGTH];
        SQLINTEGER nativeError;
        SQLSMALLINT actualMsgLen;

        SQLGetDiagRec(SQL_HANDLE_DBC, dbc, 1, sqlState, &nativeError, msg, sizeof(msg), &actualMsgLen);
        printf("Connection failed: %s\n", msg);
    }

    // Release connection and environment resources.
    SQLFreeHandle(SQL_HANDLE_DBC, dbc);
    SQLFreeHandle(SQL_HANDLE_ENV, env);

    return 0;
}

Connection established.
database: default
database: information_schema