C常用操作sqlite3函数

不顾一切的去想，于是我们有了梦想。脚踏实地的去做，于是梦想成了现实

#include<stdio.h>
#include<sqlite3.h>
#include<stdlib.h>

int main(int argc, char** args)
{
    // Create an int variable for storing the return code for each call
    int retval;

    // The number of queries to be handled,size of each query and pointer
    int q_cnt = 5,q_size = 150,ind = 0;
    char **queries = malloc(sizeof(char) * q_cnt * q_size);

    // A prepered statement for fetching tables
    sqlite3_stmt *stmt;

    // Create a handle for database connection, create a pointer to sqlite3
    sqlite3 *handle;

    // try to create the database. If it doesnt exist, it would be created
    // pass a pointer to the pointer to sqlite3, in short sqlite3**
    retval = sqlite3_open("sampledb.sqlite3",&handle);
    // If connection failed, handle returns NULL
    if(retval)
    {
        printf("Database connection failed\n");
        return -1;
    }
    printf("Connection successful\n");

    // Create the SQL query for creating a table
    char create_table[100] = "CREATE TABLE IF NOT EXISTS users (uname TEXT PRIMARY KEY,pass TEXT NOT NULL,activated INTEGER)";

    // Execute the query for creating the table
    retval = sqlite3_exec(handle,create_table,0,0,0);

    // Insert first row and second row
    queries[ind++] = "INSERT INTO users VALUES('manish','mani',1)";
    retval = sqlite3_exec(handle,queries[ind-1],0,0,0);
    queries[ind++] = "INSERT INTO users VALUES('mehul','pulsar',0)";
    retval = sqlite3_exec(handle,queries[ind-1],0,0,0);

    // select those rows from the table
    queries[ind++] = "SELECT * from users";
    retval = sqlite3_prepare_v2(handle,queries[ind-1],-1,&stmt,0);
    if(retval)
    {
        printf("Selecting data from DB Failed\n");
        return -1;
    }

    // Read the number of rows fetched
    int cols = sqlite3_column_count(stmt);

    while(1)
    {
        // fetch a row's status
        retval = sqlite3_step(stmt);

        if(retval == SQLITE_ROW)
        {
            // SQLITE_ROW means fetched a row

            // sqlite3_column_text returns a const void* , typecast it to const char*
            for(int col=0 ; col<cols;col++)
            {
                const char *val = (const char*)sqlite3_column_text(stmt,col);
                printf("%s = %s\t",sqlite3_column_name(stmt,col),val);
            }
            printf("\n");
        }
        else if(retval == SQLITE_DONE)
        {
            // All rows finished
            printf("All rows fetched\n");
            break;
        }
        else
        {
            // Some error encountered
            printf("Some error encountered\n");
            return -1;
        }
    }

    // Close the handle to free memory
    sqlite3_close(handle);
    return 0;
Save the code in a file named, say dataman.c , compile it using the command

gcc dataman.c -o dataman -l sqlite3 –std=c99