update to support postgresql and add godocs

db/postgres.go

@@ -0,0 +1,79 @@
+package db
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"log/slog"
+	"regexp"
+	"strings"
+	"vctp/db/queries"
+
+	_ "github.com/jackc/pgx/v5/stdlib"
+	"github.com/jmoiron/sqlx"
+)
+
+type PostgresDB struct {
+	logger  *slog.Logger
+	db      *sqlx.DB
+	queries *queries.Queries
+}
+
+var _ Database = (*PostgresDB)(nil)
+
+func (d *PostgresDB) DB() *sqlx.DB {
+	return d.db
+}
+
+func (d *PostgresDB) Queries() Querier {
+	return d.queries
+}
+
+func (d *PostgresDB) Logger() *slog.Logger {
+	return d.logger
+}
+
+func (d *PostgresDB) Close() error {
+	return d.db.Close()
+}
+
+func newPostgresDB(logger *slog.Logger, dsn string) (*PostgresDB, error) {
+	if strings.TrimSpace(dsn) == "" {
+		return nil, fmt.Errorf("postgres DSN is required")
+	}
+	db, err := sqlx.Open("pgx", dsn)
+	if err != nil {
+		return nil, err
+	}
+	db.SetMaxOpenConns(10)
+
+	rebindDB := rebindDBTX{db: db}
+	return &PostgresDB{logger: logger, db: db, queries: queries.New(rebindDB)}, nil
+}
+
+type rebindDBTX struct {
+	db *sqlx.DB
+}
+
+func (r rebindDBTX) ExecContext(ctx context.Context, query string, args ...interface{}) (sql.Result, error) {
+	return r.db.ExecContext(ctx, rebindQuery(query), args...)
+}
+
+func (r rebindDBTX) PrepareContext(ctx context.Context, query string) (*sql.Stmt, error) {
+	return r.db.PrepareContext(ctx, rebindQuery(query))
+}
+
+func (r rebindDBTX) QueryContext(ctx context.Context, query string, args ...interface{}) (*sql.Rows, error) {
+	return r.db.QueryContext(ctx, rebindQuery(query), args...)
+}
+
+func (r rebindDBTX) QueryRowContext(ctx context.Context, query string, args ...interface{}) *sql.Row {
+	return r.db.QueryRowContext(ctx, rebindQuery(query), args...)
+}
+
+var numberedPlaceholderRe = regexp.MustCompile(`\?\d+`)
+
+func rebindQuery(query string) string {
+	unindexed := numberedPlaceholderRe.ReplaceAllString(query, "?")
+	return sqlx.Rebind(sqlx.DOLLAR, unindexed)
+}