Streaming data from the client using COPY LOCAL

COPY LOCAL streams data from a client system file to your Vertica database.

COPY LOCAL streams data from a client system file to your Vertica database. This statement works through the ODBC driver, which simplifies the task of transferring data files from the client to the server.

COPY LOCAL works transparently through the ODBC driver. When a client application executes a COPY LOCAL statement, the ODBC driver reads and streams the data file from the client to the server.

This example demonstrates loading data from the client system using the COPY LOCAL statement:

// Some standard headers
#include <stdio.h>
#include <stdlib.h>
// Only needed for Windows clients
// #include <windows.h>
// Standard ODBC headers
#include <sql.h>
#include <sqltypes.h>
#include <sqlext.h>
int main()
{
    // Set up the ODBC environment
    SQLRETURN ret;
    SQLHENV hdlEnv;
    ret = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &hdlEnv);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not allocate a handle.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Allocated an environment handle.\n");
    }
    // Tell ODBC that the application uses ODBC 3.
    ret = SQLSetEnvAttr(hdlEnv, SQL_ATTR_ODBC_VERSION,
        (SQLPOINTER) SQL_OV_ODBC3, SQL_IS_UINTEGER);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not set application version to ODBC3.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Set application to ODBC 3.\n");
    }
    // Allocate a database handle.
    SQLHDBC hdlDbc;
    ret = SQLAllocHandle(SQL_HANDLE_DBC, hdlEnv, &hdlDbc);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not aalocate a database handle.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Set application to ODBC 3.\n");
    }
    // Connect to the database
    printf("Connecting to database.\n");
    const char *dsnName = "ExampleDB";
    const char* userID = "dbadmin";
    const char* passwd = "password123";
    ret = SQLConnect(hdlDbc, (SQLCHAR*)dsnName,
        SQL_NTS,(SQLCHAR*)userID,SQL_NTS,
        (SQLCHAR*)passwd, SQL_NTS);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not connect to database.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Connected to database.\n");
    }

    // Set up a statement handle
    SQLHSTMT hdlStmt;
    SQLAllocHandle(SQL_HANDLE_STMT, hdlDbc, &hdlStmt);


    // Create table to hold the data
    SQLExecDirect(hdlStmt, (SQLCHAR*)"DROP TABLE IF EXISTS customers",
        SQL_NTS);
    SQLExecDirect(hdlStmt, (SQLCHAR*)"CREATE TABLE customers"
        "(Last_Name char(50) NOT NULL, First_Name char(50),Email char(50), "
        "Phone_Number char(15));",
        SQL_NTS);

    // Run the copy command to load data.
    ret=SQLExecDirect(hdlStmt, (SQLCHAR*)"COPY customers "
        "FROM LOCAL '/home/dbadmin/customers.txt'",
        SQL_NTS);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Data was not successfully loaded.\n");
        exit(EXIT_FAILURE);
    } else {
        // Get number of rows added.
        SQLLEN numRows;
        ret=SQLRowCount(hdlStmt, &numRows);
        printf("Successfully inserted %d rows.\n", numRows);
    }

    // COPY commits automatically, unless it is told not to, so
    // there is no need to commit the transaction.

    // Clean up
    printf("Free handles.\n");
    ret = SQLDisconnect( hdlDbc );
    if(!SQL_SUCCEEDED(ret)) {
        printf("Error disconnecting. Transaction still open?\n");
        exit(EXIT_FAILURE);
    }
    SQLFreeHandle(SQL_HANDLE_STMT, hdlStmt);
    SQLFreeHandle(SQL_HANDLE_DBC, hdlDbc);
    SQLFreeHandle(SQL_HANDLE_ENV, hdlEnv);
    exit(EXIT_SUCCESS);
}

This example is essentially the same as the example shown in Using the COPY statement, except it uses the COPY statement's LOCAL option to load data from the client system rather than from the file system of the database node.