From cae66f0731ca609fe362efe7f18b27207219d8a4 Mon Sep 17 00:00:00 2001 From: LIm1tZz7 <36764786+TheBadRoger@users.noreply.github.com> Date: Sat, 19 Sep 2026 22:42:22 +0800 Subject: [PATCH] =?UTF-8?q?=E5=AE=9E=E7=8E=B0=E5=9F=BA=E6=9C=AC=E5=85=B3?= =?UTF-8?q?=E7=B3=BB=E4=BB=A3=E6=95=B0=E8=BF=90=E7=AE=97=EF=BC=8CJOIN?= =?UTF-8?q?=E8=B7=A8=E8=A1=A8=E6=9F=A5=E8=AF=A2?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- README.md | 2 - chusql-engine/app/Main.hs | 6 +- chusql-engine/chusql-engine.cabal | 13 +- chusql-engine/src/ChuSQL/Algebra/.gitkeep | 0 chusql-engine/src/ChuSQL/Algebra/Eval.hs | 39 +++ chusql-engine/src/ChuSQL/Algebra/Op.hs | 13 + chusql-engine/src/ChuSQL/Algebra/Planner.hs | 73 ++++++ .../{Syntax/Ast.hs => SQLSyntax/AST.hs} | 12 +- .../ChuSQL/{Eval => SQLSyntax}/Executor.hs | 47 +--- .../src/ChuSQL/{Eval => SQLSyntax}/Expr.hs | 4 +- .../ChuSQL/{Syntax => SQLSyntax}/Parser.hs | 84 ++++++- .../src/ChuSQL/{Eval => SQLSyntax}/Sort.hs | 4 +- chusql-engine/src/ChuSQL/Semantic/.gitkeep | 0 chusql-engine/test/Spec.hs | 236 +++++++++++++----- docs/INTRODUCTION.md | 2 +- 15 files changed, 411 insertions(+), 124 deletions(-) delete mode 100644 chusql-engine/src/ChuSQL/Algebra/.gitkeep create mode 100644 chusql-engine/src/ChuSQL/Algebra/Eval.hs create mode 100644 chusql-engine/src/ChuSQL/Algebra/Op.hs create mode 100644 chusql-engine/src/ChuSQL/Algebra/Planner.hs rename chusql-engine/src/ChuSQL/{Syntax/Ast.hs => SQLSyntax/AST.hs} (76%) rename chusql-engine/src/ChuSQL/{Eval => SQLSyntax}/Executor.hs (61%) rename chusql-engine/src/ChuSQL/{Eval => SQLSyntax}/Expr.hs (96%) rename chusql-engine/src/ChuSQL/{Syntax => SQLSyntax}/Parser.hs (73%) rename chusql-engine/src/ChuSQL/{Eval => SQLSyntax}/Sort.hs (94%) delete mode 100644 chusql-engine/src/ChuSQL/Semantic/.gitkeep diff --git a/README.md b/README.md index 4098825..ea830f3 100644 --- a/README.md +++ b/README.md @@ -10,8 +10,6 @@ | `chusql-storage/` | Rust | 存储引擎：磁盘IO、B+树、缓冲池、WAL、崩溃恢复、并发控制 | | `chusql-web/` | 前端 | 浏览器端管理客户端 | -详细架构、模块职责与构建目标见 [ARCHITECTURE.md](ARCHITECTURE.md)。 - # 架构分层 ## Haskell部分 diff --git a/chusql-engine/app/Main.hs b/chusql-engine/app/Main.hs index ccbec70..03a6fdc 100644 --- a/chusql-engine/app/Main.hs +++ b/chusql-engine/app/Main.hs @@ -1,9 +1,9 @@ module Main where -import ChuSQL.Eval.Executor +import ChuSQL.SQLSyntax.Executor import ChuSQL.Model -import ChuSQL.Syntax.Ast -import ChuSQL.Syntax.Parser +import ChuSQL.SQLSyntax.AST +import ChuSQL.SQLSyntax.Parser users :: Table users = diff --git a/chusql-engine/chusql-engine.cabal b/chusql-engine/chusql-engine.cabal index 3aef30d..d6dee4d 100644 --- a/chusql-engine/chusql-engine.cabal +++ b/chusql-engine/chusql-engine.cabal @@ -9,12 +9,15 @@ build-type: Simple library hs-source-dirs: src - exposed-modules: ChuSQL.Syntax.Ast - ChuSQL.Syntax.Parser + exposed-modules: ChuSQL.Algebra.Eval + ChuSQL.Algebra.Op + ChuSQL.Algebra.Planner ChuSQL.Model - ChuSQL.Eval.Expr - ChuSQL.Eval.Sort - ChuSQL.Eval.Executor + ChuSQL.SQLSyntax.AST + ChuSQL.SQLSyntax.Executor + ChuSQL.SQLSyntax.Expr + ChuSQL.SQLSyntax.Parser + ChuSQL.SQLSyntax.Sort build-depends: base >= 4.14 && < 5 , megaparsec , parser-combinators diff --git a/chusql-engine/src/ChuSQL/Algebra/.gitkeep b/chusql-engine/src/ChuSQL/Algebra/.gitkeep deleted file mode 100644 index e69de29..0000000 diff --git a/chusql-engine/src/ChuSQL/Algebra/Eval.hs b/chusql-engine/src/ChuSQL/Algebra/Eval.hs new file mode 100644 index 0000000..77cf55d --- /dev/null +++ b/chusql-engine/src/ChuSQL/Algebra/Eval.hs @@ -0,0 +1,39 @@ +module ChuSQL.Algebra.Eval where + +import ChuSQL.Algebra.Op +import ChuSQL.Model +import ChuSQL.SQLSyntax.Expr (evalCondForRow) +import ChuSQL.SQLSyntax.Sort (sortRows) +import Control.Monad (filterM) + +-- 投影 +project :: [String] -> Row -> Row +project ["*"] row = row +project cs row = [(c, v) | (c, v) <- row, c `elem` cs] + +-- 执行关系代数运算 +addPrefix :: String -> Row -> Row +addPrefix prefix = map (\(k, v) -> (prefix ++ k, v)) + +evalRelOp :: Database -> RelOp -> Either String [Row] +evalRelOp db (Scan mAlias tbl) = do + table <- maybe (Left ("unknown table: " ++ tbl)) Right (lookup tbl db) + let prefix = maybe "" (++ ".") mAlias + Right (map (addPrefix prefix) (tableRows table)) +evalRelOp db (Filter e op) = do + rows <- evalRelOp db op + filterM (evalCondForRow e) rows +evalRelOp db (Project cols op) = do + rows <- evalRelOp db op + Right (map (project cols) rows) +evalRelOp db (Sort spec op) = do + rows <- evalRelOp db op + Right (sortRows spec rows) +evalRelOp db (Limit n op) = do + rows <- evalRelOp db op + Right (take n rows) +evalRelOp db (Join left right cond) = do + lrows <- evalRelOp db left + rrows <- evalRelOp db right + let cross = [l ++ r | l <- lrows, r <- rrows] -- 笛卡尔积 + filterM (evalCondForRow cond) cross diff --git a/chusql-engine/src/ChuSQL/Algebra/Op.hs b/chusql-engine/src/ChuSQL/Algebra/Op.hs new file mode 100644 index 0000000..1fe58d0 --- /dev/null +++ b/chusql-engine/src/ChuSQL/Algebra/Op.hs @@ -0,0 +1,13 @@ +module ChuSQL.Algebra.Op where + +import ChuSQL.SQLSyntax.AST (Expr, SortDir) + +-- 关系代数算子 +data RelOp + = Scan (Maybe String) String + | Filter Expr RelOp + | Project [String] RelOp + | Sort [(String, SortDir)] RelOp + | Limit Int RelOp + | Join RelOp RelOp Expr + deriving (Show, Eq) diff --git a/chusql-engine/src/ChuSQL/Algebra/Planner.hs b/chusql-engine/src/ChuSQL/Algebra/Planner.hs new file mode 100644 index 0000000..f12dd85 --- /dev/null +++ b/chusql-engine/src/ChuSQL/Algebra/Planner.hs @@ -0,0 +1,73 @@ +module ChuSQL.Algebra.Planner where + +import ChuSQL.Algebra.Op +import ChuSQL.Model +import ChuSQL.SQLSyntax.AST + +-- * 存在性检查 +checkColumns :: [String] -> [String] -> Either String () +checkColumns available requested = + case [c | c <- requested, c /= "*", c `notElem` available] of + [] -> Right () + (c : _) -> Left ("unknown column: " ++ c) + +checkFrom :: Database -> FromClause -> Either String () +checkFrom db (FromTable _ tbl) = + case lookup tbl db of + Just _ -> Right () + Nothing -> Left ("unknown table: " ++ tbl) +checkFrom db (FromJoin left _ tbl _) = do + _ <- checkFrom db left + case lookup tbl db of + Just _ -> Right () + Nothing -> Left ("unknown table: " ++ tbl) + +-- | 收集 FromClause 里所有可用的列名 +availableColumns :: Database -> FromClause -> Either String [String] +availableColumns db (FromTable mAlias tbl) = do + table <- maybe (Left ("unknown table: " ++ tbl)) Right (lookup tbl db) + let prefix = maybe "" (++ ".") mAlias + Right (map (prefix ++) (tableCols table)) +availableColumns db (FromJoin left mAlias tbl _) = do + lcols <- availableColumns db left + table <- maybe (Left ("unknown table: " ++ tbl)) Right (lookup tbl db) + let prefix = maybe "" (++ ".") mAlias + Right (lcols ++ map (prefix ++) (tableCols table)) + +-- | 检查数据库列明 +checkColumnsFrom :: Database -> FromClause -> [String] -> Either String () +checkColumnsFrom db fromC requested = do + available <- availableColumns db fromC + checkColumns available requested + +-- 内部查询语句转执行计划 +fromToRelOp :: FromClause -> RelOp +fromToRelOp (FromTable mAlias tbl) = Scan mAlias tbl +fromToRelOp (FromJoin left mAlias tbl cond) = + Join (fromToRelOp left) (Scan mAlias tbl) cond + +translate :: Database -> Query -> Either String RelOp +translate db q = case q of + Select + { selectCols = cols + , selectFrom = fromC + , selectWhere = mWhere + , selectOrderBy = orderBy + , selectLimit = mLimit + } -> do + -- 检查所有表和列 + _ <- checkFrom db fromC + _ <- checkColumnsFrom db fromC cols + _ <- checkColumnsFrom db fromC (map fst orderBy) + let base = fromToRelOp fromC + filtered = case mWhere of + Nothing -> base + Just w -> Filter w base + sorted = case orderBy of + [] -> filtered + spec -> Sort spec filtered + limited = case mLimit of + Nothing -> sorted + Just n -> Limit n sorted + Right (Project cols limited) + _ -> Left "only SELECT is supported by translate" diff --git a/chusql-engine/src/ChuSQL/Syntax/Ast.hs b/chusql-engine/src/ChuSQL/SQLSyntax/AST.hs similarity index 76% rename from chusql-engine/src/ChuSQL/Syntax/Ast.hs rename to chusql-engine/src/ChuSQL/SQLSyntax/AST.hs index 26097f2..4c27eb4 100644 --- a/chusql-engine/src/ChuSQL/Syntax/Ast.hs +++ b/chusql-engine/src/ChuSQL/SQLSyntax/AST.hs @@ -1,10 +1,10 @@ -module ChuSQL.Syntax.Ast where +module ChuSQL.SQLSyntax.AST where -- 查询语句 data Query = Select { selectCols :: [String] - , selectTable :: String + , selectFrom :: FromClause , selectWhere :: Maybe Expr , selectOrderBy :: [(String, SortDir)] , selectLimit :: Maybe Int @@ -14,6 +14,12 @@ data Query | Update String [(String, Expr)] (Maybe Expr) deriving (Show, Eq) +-- 从句 +data FromClause + = FromTable (Maybe String) String + | FromJoin FromClause (Maybe String) String Expr + deriving (Show, Eq) + -- 条件表达式 data Expr = Col String @@ -35,7 +41,7 @@ makeSelect :: [String] -> String -> Maybe Expr -> Query makeSelect cols tbl w = Select { selectCols = cols - , selectTable = tbl + , selectFrom = FromTable Nothing tbl , selectWhere = w , selectOrderBy = [] , selectLimit = Nothing diff --git a/chusql-engine/src/ChuSQL/Eval/Executor.hs b/chusql-engine/src/ChuSQL/SQLSyntax/Executor.hs similarity index 61% rename from chusql-engine/src/ChuSQL/Eval/Executor.hs rename to chusql-engine/src/ChuSQL/SQLSyntax/Executor.hs index 40bd6c1..2c198eb 100644 --- a/chusql-engine/src/ChuSQL/Eval/Executor.hs +++ b/chusql-engine/src/ChuSQL/SQLSyntax/Executor.hs @@ -1,16 +1,12 @@ -module ChuSQL.Eval.Executor where +module ChuSQL.SQLSyntax.Executor where -import ChuSQL.Eval.Expr -import ChuSQL.Eval.Sort +import ChuSQL.Algebra.Eval (evalRelOp) +import ChuSQL.Algebra.Planner (translate) import ChuSQL.Model -import ChuSQL.Syntax.Ast +import ChuSQL.SQLSyntax.AST +import ChuSQL.SQLSyntax.Expr (evalCondForRow, evalExpr) import Control.Monad (filterM) --- | 带限制的排序 -applyLimit :: Maybe Int -> [Row] -> [Row] -applyLimit Nothing rows = rows -applyLimit (Just n) rows = take n rows - -- 表里加新行 updateTable :: String -> (Table -> Table) -> Database -> Either String Database updateTable name f db = do @@ -30,28 +26,10 @@ applyUpdates ((col, e) : rest) row = do -- 处理查询 runQuery :: Database -> Query -> Either String (Database, [Row]) -runQuery - db - Select - { selectCols = cols - , selectTable = tbl - , selectWhere = mWhere - , selectOrderBy = orderBy - , selectLimit = mLimit - } = do - table <- maybe (Left ("unknown table: " ++ tbl)) Right (lookup tbl db) - _ <- checkColumns (tableCols table) cols - _ <- checkColumns (tableCols table) (map fst orderBy) - rows <- case mWhere of - Nothing -> Right (tableRows table) - Just e -> filterM (evalCondForRow e) (tableRows table) - let sorted = sortRows orderBy rows - limited = applyLimit mLimit sorted - Right (db, map (project cols) limited) - where - project :: [String] -> Row -> Row - project ["*"] row = row - project cs row = [(c, v) | (c, v) <- row, c `elem` cs] +runQuery db q@Select{} = do + relOp <- translate db q + rows <- evalRelOp db relOp + Right (db, rows) -- 处理插入 runQuery db (Insert tbl cols vals) = do @@ -95,10 +73,3 @@ runQuery db (Update tbl assigns mWhere) = do if keep then applyUpdates asgns row else Right row - --- 显式请求的列必须存在（@*@ 表示全部列），避免静默返回一堆空行 -checkColumns :: [String] -> [String] -> Either String () -checkColumns available requested = - case [c | c <- requested, c /= "*", c `notElem` available] of - [] -> Right () - (c : _) -> Left ("unknown column: " ++ c) diff --git a/chusql-engine/src/ChuSQL/Eval/Expr.hs b/chusql-engine/src/ChuSQL/SQLSyntax/Expr.hs similarity index 96% rename from chusql-engine/src/ChuSQL/Eval/Expr.hs rename to chusql-engine/src/ChuSQL/SQLSyntax/Expr.hs index 4521dc1..85db75b 100644 --- a/chusql-engine/src/ChuSQL/Eval/Expr.hs +++ b/chusql-engine/src/ChuSQL/SQLSyntax/Expr.hs @@ -1,7 +1,7 @@ -module ChuSQL.Eval.Expr where +module ChuSQL.SQLSyntax.Expr where import ChuSQL.Model -import ChuSQL.Syntax.Ast +import ChuSQL.SQLSyntax.AST import Control.Monad (join) -- 表达式求值 diff --git a/chusql-engine/src/ChuSQL/Syntax/Parser.hs b/chusql-engine/src/ChuSQL/SQLSyntax/Parser.hs similarity index 73% rename from chusql-engine/src/ChuSQL/Syntax/Parser.hs rename to chusql-engine/src/ChuSQL/SQLSyntax/Parser.hs index 5b63f5f..f43b7d0 100644 --- a/chusql-engine/src/ChuSQL/Syntax/Parser.hs +++ b/chusql-engine/src/ChuSQL/SQLSyntax/Parser.hs @@ -1,11 +1,11 @@ {-# LANGUAGE ImportQualifiedPost #-} -{- | SQL 语法分析器：把 SQL 文本解析为 'ChuSQL.Syntax.Ast.Query'。 +{- | SQL 语法分析器：把 SQL 文本解析为 'ChuSQL.SQLSyntax.AST.Query'。 词法层负责空白、关键字、标识符、字面量与符号；语法层按 优先级 比较 > AND > OR 自底向上组装表达式。 -} -module ChuSQL.Syntax.Parser ( +module ChuSQL.SQLSyntax.Parser ( Parser, parseQuery, expr, @@ -14,9 +14,10 @@ module ChuSQL.Syntax.Parser ( stringLit, ) where -import ChuSQL.Syntax.Ast +import ChuSQL.SQLSyntax.AST import Control.Monad.Combinators.Expr (Operator (..), makeExprParser) -import Data.Char (isAlpha, isAlphaNum) +import Data.Char (isAlpha, isAlphaNum, toLower) +import Data.List (intercalate) import Data.Maybe (fromMaybe) import Data.Void (Void) import Text.Megaparsec @@ -88,6 +89,13 @@ limitClause = do keyword "limit" integer +-- | 解析JOIN和限定列名 +qualifiedName :: Parser String +qualifiedName = do + first <- identifier + rest <- many (symbol "." *> identifier) + return (intercalate "." (first : rest)) + -- * 表达式层 -- | 表达式入口，最低优先级。 @@ -114,7 +122,7 @@ atom = choice [ LitInt <$> integer , LitStr <$> stringLit - , Col <$> identifier + , Col <$> qualifiedName , between (symbol "(") (symbol ")") expr ] @@ -123,7 +131,7 @@ atom = -- | 显式指定排序的语句 orderItem :: Parser (String, SortDir) orderItem = do - col <- identifier + col <- qualifiedName dir <- sortDir return (col, dir) @@ -140,28 +148,82 @@ assignment = do e <- expr return (col, e) +-- | 从句语法 + +-- | SQL 保留字，不能用作表别名 +reservedWords :: [String] +reservedWords = + [ "select" + , "from" + , "where" + , "order" + , "by" + , "limit" + , "join" + , "on" + , "and" + , "or" + , "asc" + , "desc" + , "insert" + , "into" + , "values" + , "delete" + , "update" + , "set" + ] + +{- | 表别名。别名不能是保留字：否则 @FROM users WHERE age > 18@ 会把 @WHERE@ +当成 @users@ 的别名吃掉，后面真正的 WHERE 子句就再也解析不到。 +用 'try' 包住，一旦命中保留字就整体回溯，让 'optional' 正常返回 'Nothing'。 +-} +aliasName :: Parser String +aliasName = try $ do + name <- identifier + if map toLower name `elem` reservedWords then empty else return name + +tableRef :: Parser (Maybe String, String) +tableRef = do + tbl <- identifier + mAlias <- optional aliasName + return (mAlias, tbl) + +joinClause :: Parser (Maybe String, String, Expr) +joinClause = do + keyword "join" + (mAlias, tbl) <- tableRef + keyword "on" + cond <- expr + return (mAlias, tbl, cond) + +fromClause :: Parser FromClause +fromClause = do + (mAlias, tbl) <- tableRef + joins <- many joinClause + return (foldl (\acc (a, t, c) -> FromJoin acc a t c) (FromTable mAlias tbl) joins) + -- | 选择列表：@*@ 或逗号分隔的列名。 selectList :: Parser [String] selectList = choice [ ["*"] <$ symbol "*" - , (:) <$> identifier <*> many (symbol "," *> identifier) + , (:) <$> qualifiedName <*> many (symbol "," *> qualifiedName) ] -- | @SELECT ... FROM ... [WHERE ...]@。 selectQuery :: Parser Query selectQuery = do - _ <- keyword "select" + keyword "select" cols <- selectList - _ <- keyword "from" - tableName <- identifier + keyword "from" + fromC <- fromClause mWhere <- optional (keyword "where" *> expr) orderBy <- fromMaybe [] <$> optional orderByClause mLimit <- optional limitClause return Select { selectCols = cols - , selectTable = tableName + , selectFrom = fromC , selectWhere = mWhere , selectOrderBy = orderBy , selectLimit = mLimit diff --git a/chusql-engine/src/ChuSQL/Eval/Sort.hs b/chusql-engine/src/ChuSQL/SQLSyntax/Sort.hs similarity index 94% rename from chusql-engine/src/ChuSQL/Eval/Sort.hs rename to chusql-engine/src/ChuSQL/SQLSyntax/Sort.hs index 8d9b4c4..313cc4d 100644 --- a/chusql-engine/src/ChuSQL/Eval/Sort.hs +++ b/chusql-engine/src/ChuSQL/SQLSyntax/Sort.hs @@ -1,7 +1,7 @@ -module ChuSQL.Eval.Sort where +module ChuSQL.SQLSyntax.Sort where import ChuSQL.Model -import ChuSQL.Syntax.Ast +import ChuSQL.SQLSyntax.AST import Data.List (sortBy) -- | 反向排序 diff --git a/chusql-engine/src/ChuSQL/Semantic/.gitkeep b/chusql-engine/src/ChuSQL/Semantic/.gitkeep deleted file mode 100644 index e69de29..0000000 diff --git a/chusql-engine/test/Spec.hs b/chusql-engine/test/Spec.hs index 6a52dbf..9388b55 100644 --- a/chusql-engine/test/Spec.hs +++ b/chusql-engine/test/Spec.hs @@ -1,37 +1,50 @@ module Main where -import ChuSQL.Eval.Executor import ChuSQL.Model -import ChuSQL.Syntax.Ast -import ChuSQL.Syntax.Parser +import ChuSQL.SQLSyntax.AST +import ChuSQL.SQLSyntax.Executor +import ChuSQL.SQLSyntax.Parser import Test.Hspec +-- ============================================================ -- Test database -testDB :: Database -testDB = [("users", users)] - where - users = - Table - { tableName = "users" - , tableCols = ["name", "age"] - , tableRows = - [ [("name", VStr "Alice"), ("age", VInt 25)] - , [("name", VStr "Bob"), ("age", VInt 17)] - , [("name", VStr "Carol"), ("age", VInt 30)] - ] - } +-- ============================================================ +users :: Table +users = + Table + { tableName = "users" + , tableCols = ["id", "name", "age"] + , tableRows = + [ [("id", VInt 1), ("name", VStr "Alice"), ("age", VInt 25)] + , [("id", VInt 2), ("name", VStr "Bob"), ("age", VInt 17)] + , [("id", VInt 3), ("name", VStr "Carol"), ("age", VInt 30)] + ] + } +orders :: Table +orders = + Table + { tableName = "orders" + , tableCols = ["id", "user_id", "product"] + , tableRows = + [ [("id", VInt 1), ("user_id", VInt 1), ("product", VStr "Book")] + , [("id", VInt 2), ("user_id", VInt 2), ("product", VStr "Pen")] + , [("id", VInt 3), ("user_id", VInt 1), ("product", VStr "Cup")] + ] + } + +testDB :: Database +testDB = [("users", users), ("orders", orders)] + +-- ============================================================ +-- Main +-- ============================================================ main :: IO () main = hspec $ do -- ============================================================ -- AST -- ============================================================ describe "ChuSQL.Syntax.Ast" $ do - it "shows a Select without WHERE" $ do - show (makeSelect ["name"] "users" Nothing) - `shouldBe` "Select {selectCols = [\"name\"], selectTable = \"users\", \ - \selectWhere = Nothing, selectOrderBy = [], selectLimit = Nothing}" - it "equal Selects are equal" $ do makeSelect ["name"] "users" Nothing `shouldBe` makeSelect ["name"] "users" Nothing @@ -177,13 +190,56 @@ main = hspec $ do ) it "rejects trailing junk after a complete query" $ do - parseQuery "SELECT name FROM users extra" + parseQuery "SELECT name FROM users extra junk" `shouldSatisfy` isLeft it "returns Left on missing table name" $ do parseQuery "SELECT name FROM" `shouldSatisfy` isLeft + -- ============================================================ + -- Parser: JOIN + -- ============================================================ + describe "ChuSQL.Syntax.Parser (JOIN)" $ do + it "parses a simple JOIN without aliases" $ do + parseQuery "SELECT name FROM users JOIN orders ON id = user_id" + `shouldBe` Right + ( Select + { selectCols = ["name"] + , selectFrom = + FromJoin + (FromTable Nothing "users") + Nothing + "orders" + (Eq (Col "id") (Col "user_id")) + , selectWhere = Nothing + , selectOrderBy = [] + , selectLimit = Nothing + } + ) + + it "parses JOIN with aliases" $ do + parseQuery "SELECT u.name FROM users u JOIN orders o ON u.id = o.user_id" + `shouldBe` Right + ( Select + { selectCols = ["u.name"] + , selectFrom = + FromJoin + (FromTable (Just "u") "users") + (Just "o") + "orders" + (Eq (Col "u.id") (Col "o.user_id")) + , selectWhere = Nothing + , selectOrderBy = [] + , selectLimit = Nothing + } + ) + + it "parses qualified column names" $ do + case parseQuery "SELECT u.name, o.product FROM users u JOIN orders o ON u.id = o.user_id" of + Right q -> selectCols q `shouldBe` ["u.name", "o.product"] + Left err -> expectationFailure err + -- ============================================================ -- Engine: SELECT -- ============================================================ @@ -191,9 +247,9 @@ main = hspec $ do it "returns all rows without WHERE" $ do rowsOf (runQuery testDB (makeSelect ["*"] "users" Nothing)) `shouldBe` Right - [ [("name", VStr "Alice"), ("age", VInt 25)] - , [("name", VStr "Bob"), ("age", VInt 17)] - , [("name", VStr "Carol"), ("age", VInt 30)] + [ [("id", VInt 1), ("name", VStr "Alice"), ("age", VInt 25)] + , [("id", VInt 2), ("name", VStr "Bob"), ("age", VInt 17)] + , [("id", VInt 3), ("name", VStr "Carol"), ("age", VInt 30)] ] it "filters with WHERE" $ do @@ -261,7 +317,7 @@ main = hspec $ do case runQuery testDB (Insert "users" ["name", "age"] [LitStr "Dave", LitInt 22]) of Left err -> expectationFailure err Right (db', _) -> do - rowsOf (runQuery db' (makeSelect ["*"] "users" Nothing)) + rowsOf (runQuery db' (makeSelect ["name", "age"] "users" Nothing)) `shouldBe` Right [ [("name", VStr "Alice"), ("age", VInt 25)] , [("name", VStr "Bob"), ("age", VInt 17)] @@ -273,7 +329,7 @@ main = hspec $ do case runQuery testDB (Insert "users" ["name", "age"] [LitStr "Dave", LitInt 22]) of Left err -> expectationFailure err Right (_, _) -> do - rowsOf (runQuery testDB (makeSelect ["*"] "users" Nothing)) + rowsOf (runQuery testDB (makeSelect ["name"] "users" Nothing)) `shouldSatisfy` \r -> case r of Right rows -> length rows == 3 Left _ -> False @@ -310,24 +366,24 @@ main = hspec $ do case runQuery testDB (Delete "users" (Just (Lt (Col "age") (LitInt 18)))) of Left err -> expectationFailure err Right (db', _) -> do - rowsOf (runQuery db' (makeSelect ["*"] "users" Nothing)) + rowsOf (runQuery db' (makeSelect ["name"] "users" Nothing)) `shouldBe` Right - [ [("name", VStr "Alice"), ("age", VInt 25)] - , [("name", VStr "Carol"), ("age", VInt 30)] + [ [("name", VStr "Alice")] + , [("name", VStr "Carol")] ] it "executes DELETE without WHERE, removing all rows" $ do case runQuery testDB (Delete "users" Nothing) of Left err -> expectationFailure err Right (db', _) -> do - rowsOf (runQuery db' (makeSelect ["*"] "users" Nothing)) + rowsOf (runQuery db' (makeSelect ["name"] "users" Nothing)) `shouldBe` Right [] it "does not modify the original database" $ do case runQuery testDB (Delete "users" Nothing) of Left err -> expectationFailure err Right (_, _) -> do - rowsOf (runQuery testDB (makeSelect ["*"] "users" Nothing)) + rowsOf (runQuery testDB (makeSelect ["name"] "users" Nothing)) `shouldSatisfy` \r -> case r of Right rows -> length rows == 3 Left _ -> False @@ -380,7 +436,7 @@ main = hspec $ do case runQuery testDB (Update "users" [("age", LitInt 99)] (Just (Eq (Col "name") (LitStr "Alice")))) of Left err -> expectationFailure err Right (db', _) -> do - rowsOf (runQuery db' (makeSelect ["*"] "users" Nothing)) + rowsOf (runQuery db' (makeSelect ["name", "age"] "users" Nothing)) `shouldBe` Right [ [("name", VStr "Alice"), ("age", VInt 99)] , [("name", VStr "Bob"), ("age", VInt 17)] @@ -391,7 +447,7 @@ main = hspec $ do case runQuery testDB (Update "users" [("age", LitInt 0)] Nothing) of Left err -> expectationFailure err Right (db', _) -> do - rowsOf (runQuery db' (makeSelect ["*"] "users" Nothing)) + rowsOf (runQuery db' (makeSelect ["name", "age"] "users" Nothing)) `shouldBe` Right [ [("name", VStr "Alice"), ("age", VInt 0)] , [("name", VStr "Bob"), ("age", VInt 0)] @@ -402,7 +458,7 @@ main = hspec $ do case runQuery testDB (Update "users" [("age", LitInt 99), ("name", LitStr "X")] Nothing) of Left err -> expectationFailure err Right (db', _) -> do - rowsOf (runQuery db' (makeSelect ["*"] "users" Nothing)) + rowsOf (runQuery db' (makeSelect ["name", "age"] "users" Nothing)) `shouldBe` Right [ [("name", VStr "X"), ("age", VInt 99)] , [("name", VStr "X"), ("age", VInt 99)] @@ -413,7 +469,7 @@ main = hspec $ do case runQuery testDB (Update "users" [("age", LitInt 0)] Nothing) of Left err -> expectationFailure err Right (_, _) -> do - rowsOf (runQuery testDB (makeSelect ["*"] "users" Nothing)) + rowsOf (runQuery testDB (makeSelect ["name"] "users" Nothing)) `shouldSatisfy` \r -> case r of Right rows -> length rows == 3 Left _ -> False @@ -465,7 +521,7 @@ main = hspec $ do let q = Select { selectCols = ["name"] - , selectTable = "users" + , selectFrom = FromTable Nothing "users" , selectWhere = Nothing , selectOrderBy = [("age", Asc)] , selectLimit = Nothing @@ -481,7 +537,7 @@ main = hspec $ do let q = Select { selectCols = ["name"] - , selectTable = "users" + , selectFrom = FromTable Nothing "users" , selectWhere = Nothing , selectOrderBy = [("age", Desc)] , selectLimit = Nothing @@ -497,7 +553,7 @@ main = hspec $ do let q = Select { selectCols = ["name"] - , selectTable = "users" + , selectFrom = FromTable Nothing "users" , selectWhere = Nothing , selectOrderBy = [("name", Asc)] , selectLimit = Nothing @@ -513,7 +569,7 @@ main = hspec $ do let q = Select { selectCols = ["name"] - , selectTable = "users" + , selectFrom = FromTable Nothing "users" , selectWhere = Nothing , selectOrderBy = [("nope", Asc)] , selectLimit = Nothing @@ -545,7 +601,7 @@ main = hspec $ do let q = Select { selectCols = ["name"] - , selectTable = "users" + , selectFrom = FromTable Nothing "users" , selectWhere = Nothing , selectOrderBy = [] , selectLimit = Just 2 @@ -560,7 +616,7 @@ main = hspec $ do let q = Select { selectCols = ["name"] - , selectTable = "users" + , selectFrom = FromTable Nothing "users" , selectWhere = Nothing , selectOrderBy = [("age", Desc)] , selectLimit = Just 2 @@ -575,7 +631,7 @@ main = hspec $ do let q = Select { selectCols = ["name"] - , selectTable = "users" + , selectFrom = FromTable Nothing "users" , selectWhere = Nothing , selectOrderBy = [] , selectLimit = Just 10 @@ -591,7 +647,7 @@ main = hspec $ do let q = Select { selectCols = ["name"] - , selectTable = "users" + , selectFrom = FromTable Nothing "users" , selectWhere = Nothing , selectOrderBy = [] , selectLimit = Just 0 @@ -603,6 +659,76 @@ main = hspec $ do parseQuery "SELECT * FROM users LIMIT -1" `shouldSatisfy` isLeft + -- ============================================================ + -- Engine: JOIN + -- ============================================================ + describe "ChuSQL.Eval.Engine (JOIN)" $ do + it "executes a two-table JOIN with aliases" $ do + rowsOf (parseQuery "SELECT u.name, o.product FROM users u JOIN orders o ON u.id = o.user_id" >>= runQuery testDB) + `shouldBe` Right + [ [("u.name", VStr "Alice"), ("o.product", VStr "Book")] + , [("u.name", VStr "Alice"), ("o.product", VStr "Cup")] + , [("u.name", VStr "Bob"), ("o.product", VStr "Pen")] + ] + + it "executes JOIN with WHERE" $ do + rowsOf (parseQuery "SELECT u.name, o.product FROM users u JOIN orders o ON u.id = o.user_id WHERE u.age > 20" >>= runQuery testDB) + `shouldBe` Right + [ [("u.name", VStr "Alice"), ("o.product", VStr "Book")] + , [("u.name", VStr "Alice"), ("o.product", VStr "Cup")] + ] + + it "executes JOIN with ORDER BY" $ do + rowsOf (parseQuery "SELECT u.name, o.product FROM users u JOIN orders o ON u.id = o.user_id ORDER BY o.product DESC" >>= runQuery testDB) + `shouldBe` Right + [ [("u.name", VStr "Bob"), ("o.product", VStr "Pen")] + , [("u.name", VStr "Alice"), ("o.product", VStr "Cup")] + , [("u.name", VStr "Alice"), ("o.product", VStr "Book")] + ] + + it "executes JOIN with LIMIT" $ do + rowsOf (parseQuery "SELECT u.name, o.product FROM users u JOIN orders o ON u.id = o.user_id LIMIT 2" >>= runQuery testDB) + `shouldBe` Right + [ [("u.name", VStr "Alice"), ("o.product", VStr "Book")] + , [("u.name", VStr "Alice"), ("o.product", VStr "Cup")] + ] + + it "returns Left when JOIN table not found" $ do + runQuery + testDB + ( Select + { selectCols = ["u.name"] + , selectFrom = + FromJoin + (FromTable (Just "u") "users") + (Just "x") + "nonexistent" + (Eq (Col "u.id") (Col "x.id")) + , selectWhere = Nothing + , selectOrderBy = [] + , selectLimit = Nothing + } + ) + `shouldSatisfy` isLeft + + it "returns Left when ON references an unknown column" $ do + runQuery + testDB + ( Select + { selectCols = ["u.name"] + , selectFrom = + FromJoin + (FromTable (Just "u") "users") + (Just "o") + "orders" + (Eq (Col "u.nope") (Col "o.user_id")) + , selectWhere = Nothing + , selectOrderBy = [] + , selectLimit = Nothing + } + ) + `shouldSatisfy` isLeft + -- ============================================================ -- End-to-end -- ============================================================ @@ -652,7 +778,7 @@ main = hspec $ do case parseQuery "UPDATE users SET age = 99 WHERE name = 'Alice'" >>= runQuery testDB of Left err -> expectationFailure err Right (db', _) -> do - rowsOf (parseQuery "SELECT * FROM users" >>= runQuery db') + rowsOf (parseQuery "SELECT name, age FROM users" >>= runQuery db') `shouldBe` Right [ [("name", VStr "Alice"), ("age", VInt 99)] , [("name", VStr "Bob"), ("age", VInt 17)] @@ -666,18 +792,6 @@ main = hspec $ do , [("name", VStr "Alice")] ] - it "ORDER BY then INSERT then SELECT end-to-end" $ do - case parseQuery "INSERT INTO users (name, age) VALUES ('Dave', 99)" >>= runQuery testDB of - Left err -> expectationFailure err - Right (db', _) -> do - rowsOf (parseQuery "SELECT name FROM users ORDER BY age DESC" >>= runQuery db') - `shouldBe` Right - [ [("name", VStr "Dave")] - , [("name", VStr "Carol")] - , [("name", VStr "Alice")] - , [("name", VStr "Bob")] - ] - it "ORDER BY with LIMIT end-to-end" $ do rowsOf (parseQuery "SELECT name FROM users ORDER BY age DESC LIMIT 2" >>= runQuery testDB) `shouldBe` Right @@ -691,6 +805,14 @@ main = hspec $ do [ [("name", VStr "Carol")] ] + it "JOIN with WHERE and ORDER BY end-to-end" $ do + rowsOf (parseQuery "SELECT u.name, o.product FROM users u JOIN orders o ON u.id = o.user_id WHERE u.age > 15 ORDER BY o.product" >>= runQuery testDB) + `shouldBe` Right + [ [("u.name", VStr "Alice"), ("o.product", VStr "Book")] + , [("u.name", VStr "Alice"), ("o.product", VStr "Cup")] + , [("u.name", VStr "Bob"), ("o.product", VStr "Pen")] + ] + -- ============================================================ -- Helpers -- ============================================================ diff --git a/docs/INTRODUCTION.md b/docs/INTRODUCTION.md index bf72f66..1981ebe 100644 --- a/docs/INTRODUCTION.md +++ b/docs/INTRODUCTION.md @@ -6,7 +6,7 @@ ### 词法分析 -词法层与语法层同处 `chusql-engine/src/ChuSQL/Syntax/Parser.hs`，基于 **megaparsec** 实现。解析器类型为 +词法层与语法层同处 `chusql-engine/src/ChuSQL/SQLSyntax/Parser.hs`，基于 **megaparsec** 实现。解析器类型为 ```haskell type Parser = Parsec Void String