beer_notes_srv/sqlitedb.cpp

#include "sqlitedb.h"

#include <iostream>
#include <sstream>
#include <sqlite3.h>

SqliteDb::SqliteDb(const std::string& dbPath)
{
    open(dbPath);
}

SqliteDb::~SqliteDb()
{
    close();
}

bool SqliteDb::execute(const std::string &sql)
{
    std::ignore = sql;
    return false;
}

std::string SqliteDb::readTable(const std::string &table, const std::vector<Param>& params)
{
    std::string sql = "SELECT * FROM " + table;

    std::stringstream clause;
    std::string separator = "";
    for (const auto& [param, value] : params)
    {
        clause << separator << param << "=" << value;
        separator = " AND ";
    }

    clause.seekp(-5, std::ios_base::end);
    if (!params.empty())
        sql += " WHERE " + clause.str();

    sqlite3_stmt* stmt;

    int rc = sqlite3_prepare_v2(mDb, sql.c_str(), -1, &stmt, nullptr);
    if (rc != SQLITE_OK) {
        return std::string("SQL error: ") + sqlite3_errmsg(mDb);
    }

    int colCount = sqlite3_column_count(stmt);

    std::stringstream res;

    res << "[";
    while (sqlite3_step(stmt) == SQLITE_ROW) {
        separator = "";
        res << "{";
        for (int i = 0; i < colCount; i++) {
            const char* colName = sqlite3_column_name(stmt, i);
            const char* declType = sqlite3_column_decltype(stmt, i);
            const char* colValue = reinterpret_cast<const char*>(sqlite3_column_text(stmt, i));
            std::string type( declType );
            bool needQuote = (type == "TEXT" || type == "DATE" || !colValue);

            res << separator << colName << ":";
            if(needQuote)
                res << "\"";
            res << (colValue ? colValue : "null");
            if(needQuote)
                res << "\"";

            separator = ",";
        }
        res << "},";
    }
    res.seekp(-1, std::ios_base::end);
    res << "]";

    sqlite3_finalize(stmt);

    return res.str();
}

void SqliteDb::open(const std::string &dbPath)
{
    char *zErrMsg = 0;
    int rc = sqlite3_open(dbPath.c_str(), &mDb);
    if (rc) {
        std::cerr << "Can't open database: " << sqlite3_errmsg(mDb) << std::endl;
        sqlite3_free(zErrMsg);
    }
}

void SqliteDb::close()
{
    sqlite3_close(mDb);
}