orm: fix empty struct and simplify (#8246)

vlib/v/ast/ast.v

@@ -1156,13 +1156,12 @@ pub:
 	kind            SqlStmtKind
 	db_expr         Expr   // `db` in `sql db {`
 	object_var_name string // `user`
-	table_type      table.Type
 	pos             token.Position
 	where_expr      Expr
 	updated_columns []string // for `update set x=y`
 	update_exprs    []Expr   // for `update`
 pub mut:
-	table_name string
+	table_expr Type
 	fields     []table.Field
 }
 
@@ -1179,12 +1178,11 @@ pub:
 	order_expr  Expr
 	has_desc    bool
 	is_array    bool
-	table_type  table.Type
 	pos         token.Position
 	has_limit   bool
 	limit_expr  Expr
 pub mut:
-	table_name string
+	table_expr Type
 	fields     []table.Field
 }
 

vlib/v/checker/checker.v

@@ -5220,16 +5220,15 @@ fn (mut c Checker) sql_expr(mut node ast.SqlExpr) table.Type {
 	defer {
 		c.inside_sql = false
 	}
-	sym := c.table.get_type_symbol(node.table_type)
+	sym := c.table.get_type_symbol(node.table_expr.typ)
 	if sym.kind == .placeholder {
 		c.error('orm: unknown type `$sym.name`', node.pos)
 		return table.void_type
 	}
 	c.cur_orm_ts = sym
 	info := sym.info as table.Struct
-	fields := c.fetch_and_verify_orm_fields(info, node.pos, node.table_name)
+	fields := c.fetch_and_verify_orm_fields(info, node.table_expr.pos, sym.name)
 	node.fields = fields
-	node.table_name = sym.name
 	if node.has_where {
 		c.expr(node.where_expr)
 	}
@@ -5251,17 +5250,18 @@ fn (mut c Checker) sql_stmt(mut node ast.SqlStmt) table.Type {
 	defer {
 		c.inside_sql = false
 	}
-	if node.table_type == 0 {
+	sym := c.table.get_type_symbol(node.table_expr.typ)
-		c.error('orm: unknown type `$node.table_name`', node.pos)
+	if node.table_expr.typ == 0 {
+		c.error('orm: unknown type `$sym.name`', node.pos)
 	}
-	sym := c.table.get_type_symbol(node.table_type)
 	if sym.kind == .placeholder {
 		c.error('orm: unknown type `$sym.name`', node.pos)
 		return table.void_type
 	}
 	c.cur_orm_ts = sym
 	info := sym.info as table.Struct
-	fields := c.fetch_and_verify_orm_fields(info, node.pos, node.table_name)
+	table_sym := c.table.get_type_symbol(node.table_expr.typ)
+	fields := c.fetch_and_verify_orm_fields(info, node.table_expr.pos, table_sym.name)
 	node.fields = fields
 	c.expr(node.db_expr)
 	if node.kind == .update {
@@ -5278,6 +5278,7 @@ fn (mut c Checker) fetch_and_verify_orm_fields(info table.Struct, pos token.Posi
 		[table.string_type, table.int_type, table.bool_type] && !it.attrs.contains('skip'))
 	if fields.len == 0 {
 		c.error('V orm: select: empty fields in `$table_name`', pos)
+		return []table.Field{}
 	}
 	if fields[0].name != 'id' {
 		c.error('V orm: `id int` must be the first field in `$table_name`', pos)

vlib/v/checker/tests/orm_empty_struct.out

@@ -0,0 +1,7 @@
+vlib/v/checker/tests/orm_empty_struct.vv:9:15: error: V orm: select: empty fields in `Person`
+    7 |     db := sqlite.connect(':memory:')?
+    8 |     _ := sql db {
+    9 |         select from Person
+      |                     ~~~~~~
+   10 |     }
+   11 | }

vlib/v/checker/tests/orm_empty_struct.vv

@@ -0,0 +1,11 @@
+import sqlite
+
+struct Person {
+}
+
+fn main() {
+	db := sqlite.connect(':memory:')?
+	_ := sql db {
+		select from Person
+	}
+}

vlib/v/fmt/fmt.v

@@ -1327,8 +1327,8 @@ pub fn (mut f Fmt) sql_expr(node ast.SqlExpr) {
 	f.writeln(' {')
 	f.write('\t')
 	f.write('select ')
-	esym := f.table.get_type_symbol(node.table_type)
+	esym := f.table.get_type_symbol(node.table_expr.typ)
-	table_name := esym.name
+	table_name := util.strip_mod_name(esym.name)
 	if node.is_count {
 		f.write('count ')
 	} else {
@@ -1342,7 +1342,7 @@ pub fn (mut f Fmt) sql_expr(node ast.SqlExpr) {
 			f.write(' ')
 		}
 	}
-	f.write('from ${util.strip_mod_name(table_name)}')
+	f.write('from $table_name')
 	if node.has_where {
 		f.write(' where ')
 		f.expr(node.where_expr)
@@ -2366,12 +2366,13 @@ pub fn (mut f Fmt) sql_stmt(node ast.SqlStmt) {
 	f.write('sql ')
 	f.expr(node.db_expr)
 	f.writeln(' {')
+	table_name := util.strip_mod_name(f.table.get_type_symbol(node.table_expr.typ).name)
 	match node.kind {
 		.insert {
-			f.writeln('\tinsert $node.object_var_name into ${util.strip_mod_name(node.table_name)}')
+			f.writeln('\tinsert $node.object_var_name into $table_name')
 		}
 		.update {
-			f.write('\tupdate ${util.strip_mod_name(node.table_name)} set ')
+			f.write('\tupdate $table_name set ')
 			for i, col in node.updated_columns {
 				f.write('$col = ')
 				f.expr(node.update_exprs[i])
@@ -2387,7 +2388,7 @@ pub fn (mut f Fmt) sql_stmt(node ast.SqlStmt) {
 			f.writeln('')
 		}
 		.delete {
-			f.write('\tdelete from ${util.strip_mod_name(node.table_name)} where ')
+			f.write('\tdelete from $table_name where ')
 			f.expr(node.where_expr)
 			f.writeln('')
 		}

vlib/v/gen/sql.v

@@ -26,12 +26,13 @@ fn (mut g Gen) sql_stmt(node ast.SqlStmt) {
 	g.expr(node.db_expr)
 	g.writeln(';')
 	g.write('sqlite3_stmt* $g.sql_stmt_name = ${dbtype}__DB_init_stmt($db_name, _SLIT("')
+	table_name := util.strip_mod_name(g.table.get_type_symbol(node.table_expr.typ).name)
 	if node.kind == .insert {
-		g.write('INSERT INTO `${util.strip_mod_name(node.table_name)}` (')
+		g.write('INSERT INTO `$table_name` (')
 	} else if node.kind == .update {
-		g.write('UPDATE `${util.strip_mod_name(node.table_name)}` SET ')
+		g.write('UPDATE `$table_name` SET ')
 	} else if node.kind == .delete {
-		g.write('DELETE FROM `${util.strip_mod_name(node.table_name)}` ')
+		g.write('DELETE FROM `$table_name` ')
 	}
 	if node.kind == .insert {
 		for i, field in node.fields {
@@ -108,9 +109,10 @@ fn (mut g Gen) sql_select_expr(node ast.SqlExpr) {
 	*/
 	cur_line := g.go_before_stmt(0)
 	mut sql_query := 'SELECT '
+	table_name := util.strip_mod_name(g.table.get_type_symbol(node.table_expr.typ).name)
 	if node.is_count {
 		// `select count(*) from User`
-		sql_query += 'COUNT(*) FROM `${util.strip_mod_name(node.table_name)}` '
+		sql_query += 'COUNT(*) FROM `$table_name` '
 	} else {
 		// `select id, name, country from User`
 		for i, field in node.fields {
@@ -119,7 +121,7 @@ fn (mut g Gen) sql_select_expr(node ast.SqlExpr) {
 				sql_query += ', '
 			}
 		}
-		sql_query += ' FROM `${util.strip_mod_name(node.table_name)}`'
+		sql_query += ' FROM `$table_name`'
 	}
 	if node.has_where {
 		sql_query += ' WHERE '

vlib/v/parser/sql.v

@@ -20,6 +20,7 @@ fn (mut p Parser) sql_expr() ast.Expr {
 		p.check_name() // from
 		typ = table.int_type
 	}
+	table_pos := p.tok.position()
 	table_type := p.parse_type() // `User`
 	mut where_expr := ast.Expr{}
 	has_where := p.tok.kind == .name && p.tok.lit == 'where'
@@ -89,7 +90,6 @@ fn (mut p Parser) sql_expr() ast.Expr {
 		is_count: is_count
 		typ: typ
 		db_expr: db_expr
-		table_type: table_type
 		where_expr: where_expr
 		has_where: has_where
 		has_limit: has_limit
@@ -101,6 +101,10 @@ fn (mut p Parser) sql_expr() ast.Expr {
 		has_desc: has_desc
 		is_array: !query_one
 		pos: pos
+		table_expr: ast.Type{
+			typ: table_type
+			pos: table_pos
+		}
 	}
 }
 
@@ -127,18 +131,15 @@ fn (mut p Parser) sql_stmt() ast.SqlStmt {
 		kind = .update
 	}
 	mut inserted_var_name := ''
-	mut table_name := ''
+	mut table_type := table.Type(0)
 	if kind != .delete {
+		if kind == .update {
+			table_type = p.parse_type()
+		} else if kind == .insert {
 			expr := p.expr(0)
-		match expr {
+			if expr is ast.Ident {
-			ast.Ident {
-				if kind == .insert {
 				inserted_var_name = expr.name
-				} else if kind == .update {
+			} else {
-					table_name = expr.name
-				}
-			}
-			else {
 				p.error('can only insert variables')
 				return ast.SqlStmt{}
 			}
@@ -170,26 +171,18 @@ fn (mut p Parser) sql_stmt() ast.SqlStmt {
 		p.error('expecting `from`')
 		return ast.SqlStmt{}
 	}
-	mut table_type := table.Type(0)
+
+	mut table_pos := p.tok.position()
 	mut where_expr := ast.Expr{}
 	if kind == .insert {
-		table_type = p.parse_type() // `User`
+		table_pos = p.tok.position()
-		sym := p.table.get_type_symbol(table_type)
+		table_type = p.parse_type()
-		// info := sym.info as table.Struct
-		// fields := info.fields.filter(it.typ in [table.string_type, table.int_type, table.bool_type])
-		table_name = sym.name
 	} else if kind == .update {
-		if !p.pref.is_fmt {
-			// NB: in vfmt mode, v parses just a single file and table_name may not have been registered
-			idx := p.table.find_type_idx(p.prepend_mod(table_name))
-			table_type = table.new_type(idx)
-		}
 		p.check_sql_keyword('where') or { return ast.SqlStmt{} }
 		where_expr = p.expr(0)
 	} else if kind == .delete {
+		table_pos = p.tok.position()
 		table_type = p.parse_type()
-		sym := p.table.get_type_symbol(table_type)
-		table_name = sym.name
 		p.check_sql_keyword('where') or { return ast.SqlStmt{} }
 		where_expr = p.expr(0)
 	}
@@ -197,8 +190,10 @@ fn (mut p Parser) sql_stmt() ast.SqlStmt {
 	pos.last_line = p.prev_tok.line_nr
 	return ast.SqlStmt{
 		db_expr: db_expr
-		table_name: table_name
+		table_expr: ast.Type{
-		table_type: table_type
+			typ: table_type
+			pos: table_pos
+		}
 		object_var_name: inserted_var_name
 		pos: pos
 		updated_columns: updated_columns