first version of dbPrompt = basic usage

dbPrompt.go

@@ -0,0 +1,211 @@
+package main
+
+import (
+	"database/sql"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"os"
+	"path/filepath"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+
+	_ "github.com/go-sql-driver/mysql"
+)
+
+// Config struct for database connection
+type Config struct {
+	Username string `json:"username"`
+	Password string `json:"password"`
+	Hostname string `json:"hostname"`
+	Port     int    `json:"port"`
+	Database string `json:"database"`
+}
+
+// QueryRequest from the frontend
+type QueryRequest struct {
+	ID    string `json:"id"`
+	Query string `json:"query"`
+}
+
+// QueryResult represents a single historical query execution
+type QueryResult struct {
+	ID        string          `json:"id"`
+	Query     string          `json:"query"`
+	Timestamp int64           `json:"timestamp"`
+	Error     string          `json:"error,omitempty"`
+	Columns   []string        `json:"columns,omitempty"`
+	Rows      [][]interface{} `json:"rows,omitempty"`
+	RowsAffected int64        `json:"rowsAffected,omitempty"`
+}
+
+var db *sql.DB
+var historyDir = "./history"
+
+func main() {
+	// Load configuration
+	file, err := os.Open("config.json")
+	if err != nil {
+		log.Fatalf("Failed to open config file: %v", err)
+	}
+	defer file.Close()
+
+	var config Config
+	decoder := json.NewDecoder(file)
+	if err := decoder.Decode(&config); err != nil {
+		log.Fatalf("Failed to decode config: %v", err)
+	}
+
+	// Connect to the database
+	dsn := fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?parseTime=true",
+		config.Username, config.Password, config.Hostname, config.Port, config.Database)
+	db, err = sql.Open("mysql", dsn)
+	if err != nil {
+		log.Fatalf("Failed to open database connection: %v", err)
+	}
+	defer db.Close()
+
+	if err := db.Ping(); err != nil {
+		log.Fatalf("Failed to connect to the database: %v", err)
+	}
+
+	log.Println("Successfully connected to the database.")
+
+	// Ensure history directory exists
+	if _, err := os.Stat(historyDir); os.IsNotExist(err) {
+		os.Mkdir(historyDir, 0755)
+	}
+
+	// HTTP Handlers
+	http.HandleFunc("/", serveIndex)
+	http.HandleFunc("/query", handleQuery)
+	http.HandleFunc("/history", handleHistory)
+
+	log.Println("Starting server on :8080...")
+	if err := http.ListenAndServe(":8080", nil); err != nil {
+		log.Fatalf("Server failed: %v", err)
+	}
+}
+
+func serveIndex(w http.ResponseWriter, r *http.Request) {
+	http.ServeFile(w, r, "index.html")
+}
+
+func handleHistory(w http.ResponseWriter, r *http.Request) {
+	files, err := ioutil.ReadDir(historyDir)
+	if err != nil {
+		http.Error(w, "Could not read history", http.StatusInternalServerError)
+		return
+	}
+
+	var history []QueryResult
+	for _, file := range files {
+		if filepath.Ext(file.Name()) == ".json" {
+			data, err := ioutil.ReadFile(filepath.Join(historyDir, file.Name()))
+			if err != nil {
+				continue
+			}
+			var qr QueryResult
+			if err := json.Unmarshal(data, &qr); err == nil {
+				history = append(history, qr)
+			}
+		}
+	}
+
+	// Sort by timestamp, oldest first
+	sort.Slice(history, func(i, j int) bool {
+		return history[i].Timestamp < history[j].Timestamp
+	})
+
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(history)
+}
+
+func handleQuery(w http.ResponseWriter, r *http.Request) {
+	var req QueryRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	query := strings.TrimSpace(req.Query)
+	isSelect := strings.HasPrefix(strings.ToLower(query), "select") || strings.HasPrefix(strings.ToLower(query), "show") || strings.HasPrefix(strings.ToLower(query), "describe")
+
+	result := QueryResult{
+		ID:        req.ID,
+		Query:     req.Query,
+		Timestamp: time.Now().UnixNano(),
+	}
+
+    // Generate new ID if it's a new query
+    if result.ID == "" {
+        result.ID = strconv.FormatInt(result.Timestamp, 10)
+    }
+
+	if isSelect {
+		// It's a query that returns rows
+		rows, err := db.Query(query)
+		if err != nil {
+			result.Error = err.Error()
+		} else {
+			defer rows.Close()
+			cols, _ := rows.Columns()
+			result.Columns = cols
+			
+			for rows.Next() {
+                // Create a slice of interface{}'s to represent a row
+                columns := make([]interface{}, len(cols))
+                columnPointers := make([]interface{}, len(cols))
+                for i := range columns {
+                    columnPointers[i] = &columns[i]
+                }
+
+                // Scan the result into the column pointers...
+                if err := rows.Scan(columnPointers...); err != nil {
+                    result.Error = err.Error()
+                    break
+                }
+				
+				// Convert byte slices to strings for better JSON representation
+				for i, col := range columns {
+					if b, ok := col.([]byte); ok {
+						columns[i] = string(b)
+					}
+				}
+
+                result.Rows = append(result.Rows, columns)
+			}
+			if err := rows.Err(); err != nil {
+				result.Error = err.Error()
+			}
+		}
+	} else {
+		// It's a statement like INSERT, UPDATE, DELETE
+		res, err := db.Exec(query)
+		if err != nil {
+			result.Error = err.Error()
+		} else {
+			affected, err := res.RowsAffected()
+			if err != nil {
+				result.Error = err.Error()
+			} else {
+				result.RowsAffected = affected
+			}
+		}
+	}
+
+	// Save to history
+	filePath := filepath.Join(historyDir, result.ID+".json")
+	fileData, _ := json.MarshalIndent(result, "", "  ")
+	if err := ioutil.WriteFile(filePath, fileData, 0644); err != nil {
+		log.Printf("Failed to write history file %s: %v", filePath, err)
+		// Don't send a server error back to client, they can still see the result
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(result)
+}