added Connection.ValidateColumnName, rename db.QueryRowStruct to QueryRow, rename Connection.StructFieldNamer to StructFieldMapper

Author: ungerik

connection.go

@@ -24,12 +24,12 @@ type Connection interface {
 	// context for its operations.
 	WithContext(ctx context.Context) Connection
 
-	// WithStructFieldNamer returns a copy of the connection
-	// that will use the passed StructFieldNamer.
-	WithStructFieldNamer(namer StructFieldMapper) Connection
+	// WithStructFieldMapper returns a copy of the connection
+	// that will use the passed StructFieldMapper.
+	WithStructFieldMapper(StructFieldMapper) Connection
 
-	// StructFieldNamer used by methods of this Connection.
-	StructFieldNamer() StructFieldMapper
+	// StructFieldMapper used by methods of this Connection.
+	StructFieldMapper() StructFieldMapper
 
 	// Ping returns an error if the database
 	// does not answer on this connection
@@ -45,6 +45,11 @@ type Connection interface {
 	// to create this connection.
 	Config() *Config
 
+	// ValidateColumnName returns an error
+	// if the passed name is not valid for a
+	// column of the connection's database.
+	ValidateColumnName(name string) error
+
 	// Now returns the result of the SQL now()
 	// function for the current connection.
 	// Useful for getting the timestamp of a
@@ -67,12 +72,12 @@ type Connection interface {
 	InsertReturning(table string, values Values, returning string) RowScanner
 
 	// InsertStruct inserts a new row into table using the connection's
-	// StructFieldNamer to map struct fields to column names.
+	// StructFieldMapper to map struct fields to column names.
 	// Optional ColumnFilter can be passed to ignore mapped columns.
 	InsertStruct(table string, rowStruct any, ignoreColumns ...ColumnFilter) error
 
 	// InsertUniqueStruct inserts a new row into table using the connection's
-	// StructFieldNamer to map struct fields to column names.
+	// StructFieldMapper to map struct fields to column names.
 	// Optional ColumnFilter can be passed to ignore mapped columns.
 	// Does nothing if the onConflict statement applies
 	// and returns if a row was inserted.

db/queryrow.go

@@ -9,20 +9,20 @@ import (
 	"github.com/domonda/go-sqldb"
 )
 
-// QueryRowStruct uses the passed pkValues to query a table row
+// QueryStruct uses the passed pkValues to query a table row
 // and scan it into a struct of type S that must have tagged fields
 // with primary key flags to identify the primary key column names
 // for the passed pkValues and a table name.
-func QueryRowStruct[S any](ctx context.Context, pkValues ...any) (row *S, err error) {
+func QueryStruct[S any](ctx context.Context, pkValues ...any) (row *S, err error) {
 	if len(pkValues) == 0 {
-		return nil, errors.New("no primaryKeyValues passed")
+		return nil, errors.New("missing primary key values")
 	}
 	t := reflect.TypeOf(row).Elem()
 	if t.Kind() != reflect.Struct {
 		return nil, fmt.Errorf("expected struct template type instead of %s", t)
 	}
 	conn := Conn(ctx)
-	table, pkColumns, err := pkColumnsOfStruct(t, conn.StructFieldNamer())
+	table, pkColumns, err := pkColumnsOfStruct(conn, t)
 	if err != nil {
 		return nil, err
 	}
@@ -40,7 +40,8 @@ func QueryRowStruct[S any](ctx context.Context, pkValues ...any) (row *S, err er
 	return row, nil
 }
 
-func pkColumnsOfStruct(t reflect.Type, mapper sqldb.StructFieldMapper) (table string, columns []string, err error) {
+func pkColumnsOfStruct(conn sqldb.Connection, t reflect.Type) (table string, columns []string, err error) {
+	mapper := conn.StructFieldMapper()
 	for i := 0; i < t.NumField(); i++ {
 		field := t.Field(i)
 		fieldTable, column, flags, ok := mapper.MapStructField(field)
@@ -55,7 +56,7 @@ func pkColumnsOfStruct(t reflect.Type, mapper sqldb.StructFieldMapper) (table st
 		}
 
 		if column == "" {
-			fieldTable, columnsEmbed, err := pkColumnsOfStruct(field.Type, mapper)
+			fieldTable, columnsEmbed, err := pkColumnsOfStruct(conn, field.Type)
 			if err != nil {
 				return "", nil, err
 			}
@@ -67,6 +68,9 @@ func pkColumnsOfStruct(t reflect.Type, mapper sqldb.StructFieldMapper) (table st
 			}
 			columns = append(columns, columnsEmbed...)
 		} else if flags.PrimaryKey() {
+			if err = conn.ValidateColumnName(column); err != nil {
+				return "", nil, fmt.Errorf("%w in struct field %s.%s", err, t, field.Name)
+			}
 			columns = append(columns, column)
 		}
 	}

errors.go

@@ -80,11 +80,11 @@ func (e connectionWithError) WithContext(ctx context.Context) Connection {
 	return connectionWithError{ctx: ctx, err: e.err}
 }
 
-func (e connectionWithError) WithStructFieldNamer(namer StructFieldMapper) Connection {
+func (e connectionWithError) WithStructFieldMapper(namer StructFieldMapper) Connection {
 	return e
 }
 
-func (e connectionWithError) StructFieldNamer() StructFieldMapper {
+func (e connectionWithError) StructFieldMapper() StructFieldMapper {
 	return DefaultStructFieldMapping
 }
 
@@ -100,6 +100,10 @@ func (e connectionWithError) Config() *Config {
 	return &Config{Err: e.err}
 }
 
+func (e connectionWithError) ValidateColumnName(name string) error {
+	return e.err
+}
+
 func (e connectionWithError) Now() (time.Time, error) {
 	return time.Time{}, e.err
 }

examples/user_demo/user_demo.go

@@ -45,7 +45,7 @@ func main() {
 		panic(err)
 	}
 
-	conn = conn.WithStructFieldNamer(&sqldb.TaggedStructFieldMapping{
+	conn = conn.WithStructFieldMapper(&sqldb.TaggedStructFieldMapping{
 		NameTag:          "col",
 		Ignore:           "ignore",
 		UntaggedNameFunc: sqldb.ToSnakeCase,

impl/connection.go

@@ -13,22 +13,24 @@ import (
 // for an existing sql.DB connection.
 // argFmt is the format string for argument placeholders like "?" or "$%d"
 // that will be replaced error messages to format a complete query.
-func Connection(ctx context.Context, db *sql.DB, config *sqldb.Config, argFmt string) sqldb.Connection {
+func Connection(ctx context.Context, db *sql.DB, config *sqldb.Config, validateColumnName func(string) error, argFmt string) sqldb.Connection {
 	return &connection{
-		ctx:              ctx,
-		db:               db,
-		config:           config,
-		structFieldNamer: sqldb.DefaultStructFieldMapping,
-		argFmt:           argFmt,
+		ctx:                ctx,
+		db:                 db,
+		config:             config,
+		structFieldNamer:   sqldb.DefaultStructFieldMapping,
+		argFmt:             argFmt,
+		validateColumnName: validateColumnName,
 	}
 }
 
 type connection struct {
-	ctx              context.Context
-	db               *sql.DB
-	config           *sqldb.Config
-	structFieldNamer sqldb.StructFieldMapper
-	argFmt           string
+	ctx                context.Context
+	db                 *sql.DB
+	config             *sqldb.Config
+	structFieldNamer   sqldb.StructFieldMapper
+	argFmt             string
+	validateColumnName func(string) error
 }
 
 func (conn *connection) clone() *connection {
@@ -47,13 +49,13 @@ func (conn *connection) WithContext(ctx context.Context) sqldb.Connection {
 	return c
 }
 
-func (conn *connection) WithStructFieldNamer(namer sqldb.StructFieldMapper) sqldb.Connection {
+func (conn *connection) WithStructFieldMapper(namer sqldb.StructFieldMapper) sqldb.Connection {
 	c := conn.clone()
 	c.structFieldNamer = namer
 	return c
 }
 
-func (conn *connection) StructFieldNamer() sqldb.StructFieldMapper {
+func (conn *connection) StructFieldMapper() sqldb.StructFieldMapper {
 	return conn.structFieldNamer
 }
 
@@ -75,6 +77,10 @@ func (conn *connection) Config() *sqldb.Config {
 	return conn.config
 }
 
+func (conn *connection) ValidateColumnName(name string) error {
+	return conn.validateColumnName(name)
+}
+
 func (conn *connection) Now() (time.Time, error) {
 	return Now(conn)
 }

impl/insert.go

@@ -84,7 +84,7 @@ func writeInsertQuery(w *strings.Builder, table, argFmt string, names []string)
 }
 
 // InsertStruct inserts a new row into table using the connection's
-// StructFieldNamer to map struct fields to column names.
+// StructFieldMapper to map struct fields to column names.
 // Optional ColumnFilter can be passed to ignore mapped columns.
 func InsertStruct(conn sqldb.Connection, table string, rowStruct any, namer sqldb.StructFieldMapper, argFmt string, ignoreColumns []sqldb.ColumnFilter) error {
 	columns, vals, err := insertStructValues(table, rowStruct, namer, ignoreColumns)
@@ -102,7 +102,7 @@ func InsertStruct(conn sqldb.Connection, table string, rowStruct any, namer sqld
 }
 
 // InsertUniqueStruct inserts a new row into table using the connection's
-// StructFieldNamer to map struct fields to column names.
+// StructFieldMapper to map struct fields to column names.
 // Optional ColumnFilter can be passed to ignore mapped columns.
 // Does nothing if the onConflict statement applies
 // and returns if a row was inserted.

impl/rowscanner.go

@@ -77,16 +77,16 @@ func (s *RowScanner) Columns() ([]string, error) {
 
 // CurrentRowScanner calls Rows.Scan without Rows.Next and Rows.Close
 type CurrentRowScanner struct {
-	Rows             Rows
-	StructFieldNamer sqldb.StructFieldMapper
+	Rows              Rows
+	StructFieldMapper sqldb.StructFieldMapper
 }
 
 func (s CurrentRowScanner) Scan(dest ...any) error {
 	return s.Rows.Scan(dest...)
 }
 
 func (s CurrentRowScanner) ScanStruct(dest any) error {
-	return ScanStruct(s.Rows, dest, s.StructFieldNamer)
+	return ScanStruct(s.Rows, dest, s.StructFieldMapper)
 }
 
 func (s CurrentRowScanner) ScanValues() ([]any, error) {
@@ -103,16 +103,16 @@ func (s CurrentRowScanner) Columns() ([]string, error) {
 
 // SingleRowScanner always uses the same Row
 type SingleRowScanner struct {
-	Row              Row
-	StructFieldNamer sqldb.StructFieldMapper
+	Row               Row
+	StructFieldMapper sqldb.StructFieldMapper
 }
 
 func (s SingleRowScanner) Scan(dest ...any) error {
 	return s.Row.Scan(dest...)
 }
 
 func (s SingleRowScanner) ScanStruct(dest any) error {
-	return ScanStruct(s.Row, dest, s.StructFieldNamer)
+	return ScanStruct(s.Row, dest, s.StructFieldMapper)
 }
 
 func (s SingleRowScanner) ScanValues() ([]any, error) {

impl/scanstruct_test.go

@@ -31,7 +31,7 @@ package impl
 
 // 	type args struct {
 // 		t     reflect.Type
-// 		namer sqldb.StructFieldNamer
+// 		namer sqldb.StructFieldMapper
 // 	}
 // 	tests := []struct {
 // 		name             string

impl/transaction.go

@@ -43,20 +43,24 @@ func (conn *transaction) WithContext(ctx context.Context) sqldb.Connection {
 	return newTransaction(parent, conn.tx, conn.opts)
 }
 
-func (conn *transaction) WithStructFieldNamer(namer sqldb.StructFieldMapper) sqldb.Connection {
+func (conn *transaction) WithStructFieldMapper(namer sqldb.StructFieldMapper) sqldb.Connection {
 	c := conn.clone()
 	c.structFieldNamer = namer
 	return c
 }
 
-func (conn *transaction) StructFieldNamer() sqldb.StructFieldMapper {
+func (conn *transaction) StructFieldMapper() sqldb.StructFieldMapper {
 	return conn.structFieldNamer
 }
 
 func (conn *transaction) Ping(timeout time.Duration) error { return conn.parent.Ping(timeout) }
 func (conn *transaction) Stats() sql.DBStats               { return conn.parent.Stats() }
 func (conn *transaction) Config() *sqldb.Config            { return conn.parent.Config() }
 
+func (conn *transaction) ValidateColumnName(name string) error {
+	return conn.parent.validateColumnName(name)
+}
+
 func (conn *transaction) Now() (time.Time, error) {
 	return Now(conn)
 }

mockconn/connection.go

@@ -49,7 +49,7 @@ func (conn *connection) WithContext(ctx context.Context) sqldb.Connection {
 	}
 }
 
-func (conn *connection) WithStructFieldNamer(namer sqldb.StructFieldMapper) sqldb.Connection {
+func (conn *connection) WithStructFieldMapper(namer sqldb.StructFieldMapper) sqldb.Connection {
 	return &connection{
 		ctx:              conn.ctx,
 		queryWriter:      conn.queryWriter,
@@ -60,7 +60,7 @@ func (conn *connection) WithStructFieldNamer(namer sqldb.StructFieldMapper) sqld
 	}
 }
 
-func (conn *connection) StructFieldNamer() sqldb.StructFieldMapper {
+func (conn *connection) StructFieldMapper() sqldb.StructFieldMapper {
 	return conn.structFieldNamer
 }
 
@@ -72,6 +72,10 @@ func (conn *connection) Config() *sqldb.Config {
 	return &sqldb.Config{Driver: "mockconn", Host: "localhost", Database: "mock"}
 }
 
+func (conn *connection) ValidateColumnName(name string) error {
+	return validateColumnName(name)
+}
+
 func (conn *connection) Ping(time.Duration) error {
 	return nil
 }