e013ff3 · squeal · git.iko.soy

git.iko.soy/squeal

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e013ff3Eitan Chatav8 years ago

squeal-postgresql/src/Squeal/PostgreSQL.hs+6−7

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unifiedsplit

@@ -21,7 +21,6 @@ We'll need some imports.

21>>> import Data.Int (Int32)

22>>> import Data.Text (Text)

23>>> import Squeal.PostgreSQL

24−>>> import qualified Data.ByteString.Char8 as Char8 (putStrLn)

26We'll use generics to easily convert between Haskell and PostgreSQL values.

25We'll use generics to easily convert between Haskell and PostgreSQL values.

@@ -81,13 +80,13 @@ let

82We can easily see the generated SQL is unsuprising looking.

81We can easily see the generated SQL is unsuprising looking.

84−>>> Char8.putStrLn $ renderDefinition setup

83+>>> printSQL setup

85CREATE TABLE "users" ("id" serial, "name" text NOT NULL, CONSTRAINT "pk_users" PRIMARY KEY ("id"));

84CREATE TABLE "users" ("id" serial, "name" text NOT NULL, CONSTRAINT "pk_users" PRIMARY KEY ("id"));

86CREATE TABLE "emails" ("id" serial, "user_id" int NOT NULL, "email" text NULL, CONSTRAINT "pk_emails" PRIMARY KEY ("id"), CONSTRAINT "fk_user_id" FOREIGN KEY ("user_id") REFERENCES "users" ("id") ON DELETE CASCADE ON UPDATE CASCADE);

85CREATE TABLE "emails" ("id" serial, "user_id" int NOT NULL, "email" text NULL, CONSTRAINT "pk_emails" PRIMARY KEY ("id"), CONSTRAINT "fk_user_id" FOREIGN KEY ("user_id") REFERENCES "users" ("id") ON DELETE CASCADE ON UPDATE CASCADE);

88Notice that @setup@ starts with an empty schema @'[]@ and produces @Schema@.

87Notice that @setup@ starts with an empty schema @'[]@ and produces @Schema@.

89In our `createTable` commands we included `TableConstraint`s to define

88In our `createTable` commands we included `TableConstraint`s to define

90−primary and foreign keys, making them somewhat complex. Our tear down

89+primary and foreign keys, making them somewhat complex. Our @teardown@

91`Definition` is simpler.

90`Definition` is simpler.

93>>> :{

92>>> :{

@@ -96,7 +95,7 @@ let

96 teardown = dropTable #emails >>> dropTable #users

95 teardown = dropTable #emails >>> dropTable #users

97:}

96:}

99−>>> Char8.putStrLn $ renderDefinition teardown

98+>>> printSQL teardown

100DROP TABLE "emails";

99DROP TABLE "emails";

101DROP TABLE "users";

100DROP TABLE "users";

102

101

@@ -130,9 +129,9 @@ let

130 OnConflictDoNothing (Returning Nil)

129 OnConflictDoNothing (Returning Nil)

131:}

130:}

132

131

133−>>> Char8.putStrLn $ renderManipulation insertUser

132+>>> printSQL insertUser

134INSERT INTO "users" ("id", "name") VALUES (DEFAULT, ($1 :: text)) ON CONFLICT DO NOTHING RETURNING "id" AS "fromOnly"

133INSERT INTO "users" ("id", "name") VALUES (DEFAULT, ($1 :: text)) ON CONFLICT DO NOTHING RETURNING "id" AS "fromOnly"

135−>>> Char8.putStrLn $ renderManipulation insertEmail

134+>>> printSQL insertEmail

136INSERT INTO "emails" ("id", "user_id", "email") VALUES (DEFAULT, ($1 :: int4), ($2 :: text)) ON CONFLICT DO NOTHING

135INSERT INTO "emails" ("id", "user_id", "email") VALUES (DEFAULT, ($1 :: int4), ($2 :: text)) ON CONFLICT DO NOTHING

137

136

138Next we write a `Query` to retrieve users from the database. We're not

137Next we write a `Query` to retrieve users from the database. We're not

@@ -152,7 +151,7 @@ let

152 (#u ! #id .== #e ! #user_id)) )

151 (#u ! #id .== #e ! #user_id)) )

153:}

152:}

154

153

155−>>> Char8.putStrLn $ renderQuery getUsers

154+>>> printSQL getUsers

156SELECT "u"."name" AS "userName", "e"."email" AS "userEmail" FROM "users" AS "u" INNER JOIN "emails" AS "e" ON ("u"."id" = "e"."user_id")

155SELECT "u"."name" AS "userName", "e"."email" AS "userEmail" FROM "users" AS "u" INNER JOIN "emails" AS "e" ON ("u"."id" = "e"."user_id")

157

156

158Now that we've defined the SQL side of things, we'll need a Haskell type

157Now that we've defined the SQL side of things, we'll need a Haskell type