feat: sql, migrations, sql postgress db setup, movie model

projects/greenlight/internal/data/models.go

@@ -0,0 +1,27 @@
+package data
+
+import (
+	"database/sql"
+	"errors"
+)
+
+// Define a custom ErrRecordNotFound error. We'll return this from our Get() method when
+// looking up a movie that doesn't exist in our database.
+var (
+	ErrRecordNotFound = errors.New("record not found")
+)
+
+// Create a Models struct which wraps the MovieModel. We'll add other models to this,
+// like a UserModel and PermissionModel, as our build progresses.
+type Models struct {
+	Movies MovieModel
+}
+
+// For ease of use, we also add a New()
+// method which returns a Models struct containing
+// the initialized MovieModel.
+func NewModels(db *sql.DB) Models {
+	return Models{
+		Movies: MovieModel{DB: db},
+	}
+}

projects/greenlight/internal/data/movies.go

@@ -1,11 +1,53 @@
 package data
 
 import (
+	"database/sql"
 	"time"
 
+	"github.com/lib/pq"
 	"greenlight.debuggingjon.dev/internal/validator"
 )
 
+// Define a MovieModel struct type which wraps a sql.DB connection pool.
+type MovieModel struct {
+	DB *sql.DB
+}
+
+// Add a placeholder method for inserting a new record in the movies table.
+func (m MovieModel) Insert(movie *Movie) error {
+	// Define the SQL query for inserting a new record in the movies table and returning
+	// the system-generated data.
+	query := `
+        INSERT INTO movies (title, year, runtime, genres) 
+        VALUES ($1, $2, $3, $4)
+        RETURNING id, created_at, version`
+
+	// Create an args slice containing the values for the placeholder parameters from
+	// the movie struct. Declaring this slice immediately next to our SQL query helps to
+	// make it nice and clear *what values are being used where* in the query.
+	args := []interface{}{movie.Title, movie.Year, movie.Runtime, pq.Array(movie.Genres)}
+
+	// Use the QueryRow() method to execute the SQL query on our connection pool,
+	// passing in the args slice as a variadic parameter and scanning the system-
+	// generated id, created_at and version values into the movie struct.
+	return m.DB.QueryRow(query, args...).Scan(&movie.ID, &movie.CreatedAt, &movie.Version)
+}
+
+// Add a placeholder method for fetching a specific record from the movies table.
+func (m MovieModel) Get(id int64) (*Movie, error) {
+	return nil, nil
+}
+
+// Add a placeholder method for updating a specific record in the “movies table.
+func (m MovieModel) Update(movie *Movie) error {
+	return nil
+}
+
+// Add a placeholder method for deleting a specific record from the movies table.
+func (m MovieModel) Delete(id int64) error {
+	return nil
+}
+
 type Movie struct {
 	ID        int64     `json:"id"`
 	CreatedAt time.Time `json:"-"` // Use the - directive