ok

0_setup/go.mod

@@ -0,0 +1,5 @@
+module 0_setup
+
+go 1.18
+
+require github.com/mattn/go-sqlite3 v1.14.15

0_setup/go.sum

@@ -0,0 +1,2 @@
+github.com/mattn/go-sqlite3 v1.14.15 h1:vfoHhTN1af61xCRSWzFIWzx2YskyMTwHLrExkBOjvxI=
+github.com/mattn/go-sqlite3 v1.14.15/go.mod h1:2eHXhiwb8IkHr+BDWZGa96P6+rkvnG63S2DGjv9HUNg=

0_setup/main.go

@@ -0,0 +1,74 @@
+package main
+
+import (
+	"database/sql"
+	"flag"
+	"fmt"
+	"log"
+	"strings"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+func main() {
+	dbpath := flag.String("db", "./db.db", "path to db file")
+	q := flag.String("q", "show tables", "query to execute")
+	flag.Parse()
+
+	query := strings.Trim(strings.TrimSpace(*q), ";")
+	if len(query) == 0 {
+		panic("refusing empty query")
+	}
+	query += ";"
+	log.Printf("%s", query)
+
+	db, err := sql.Open("sqlite3", *dbpath)
+	if err != nil {
+		panic(err)
+	}
+
+	if strings.HasPrefix(strings.ToUpper(strings.TrimSpace(query)), "SELECT") {
+		rows, err := db.Query(query)
+		if err != nil {
+			panic(err)
+		}
+		defer rows.Close()
+
+		columns, err := rows.Columns()
+		if err != nil {
+			panic(err)
+		}
+
+		ptrs := make([]any, len(columns))
+		for i := range ptrs {
+			var v interface{}
+			ptrs[i] = &v
+		}
+
+		for rows.Next() {
+			if err := rows.Scan(ptrs...); err != nil {
+				panic(err)
+			}
+			result := make([]string, len(columns))
+			for i := range ptrs {
+				ptr := ptrs[i].(*interface{})
+				result[i] = fmt.Sprintf("%s:%+v", columns[i], *ptr)
+			}
+			log.Println(result)
+		}
+	} else {
+		stmt, err := db.Prepare(query)
+		if err != nil {
+			panic(err)
+		}
+
+		result, err := stmt.Exec()
+		if err != nil {
+			panic(err)
+		}
+
+		affected, err := result.RowsAffected()
+		log.Printf("%d: %v", affected, err)
+	}
+
+}

0_setup/mvp.sh

@@ -0,0 +1,51 @@
+#! /bin/bash
+
+main() {
+   set -e
+   set -o pipefail
+
+   local bin=./0_setup
+   local cmds=(
+      'DROP TABLE IF EXISTS a'
+      'CREATE TABLE a(
+         x INT,
+         y VARCHAR(20),
+         PRIMARY KEY (x)
+      )'
+      'DROP TABLE IF EXISTS b'
+      'CREATE TABLE b(
+         x INT,
+         y VARCHAR(20),
+         PRIMARY KEY (x)
+      )'
+      'SELECT * FROM a'
+      'INSERT INTO a
+         (x, y)
+         VALUES
+         (4, "a")
+      '
+      'SELECT * FROM a'
+      'SELECT * FROM b'
+      'INSERT INTO b
+         (x, y)
+         VALUES
+         (5, "b")
+      '
+      'SELECT * FROM b'
+      'UPDATE b
+         SET x=4
+         WHERE y="b"
+      '
+      'SELECT * FROM b'
+      'SELECT * FROM a JOIN b WHERE a.x == b.x'
+      'SELECT a.y, b.y FROM a JOIN b WHERE a.x == b.x'
+   )
+
+   for cmd in "${cmds[@]}"; do
+      echo =================
+      $bin -q "$cmd"
+      echo
+   done
+}
+
+main "$@"