Add unqiue constraint for model fields

May be specified by adding #[unique] to a field

butane/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "butane"
-version = "0.3.0"
+version = "0.3.1"
 authors = ["James Oakley <[email protected]>"]
 edition = "2018"
 description = "An ORM with a focus on simplicity and on writing Rust, not SQL."
@@ -23,8 +23,8 @@ tls = ["butane_core/tls"]
 uuid = ["butane_core/uuid", "butane_codegen/uuid"]
 
 [dependencies]
-butane_codegen = { path = "../butane_codegen", version = "0.3.0" }
-butane_core = { path = "../butane_core", version = "0.3.0" }
+butane_codegen = { path = "../butane_codegen", version = "0.3.1" }
+butane_core = { path = "../butane_core", version = "0.3.1" }
 
 
 [dev-dependencies]
@@ -38,6 +38,7 @@ proc-macro2="1.0"
 once_cell="1.5.2"
 postgres = { version = "0.19", features=["with-geo-types-0_7"] }
 r2d2_for_test = {package="r2d2", version = "0.8"}
+rusqlite = "0.25"
 uuid_for_test = {package="uuid", version = "0.8", features=["v4"] }
 
 [package.metadata.docs.rs]

butane/tests/basic.rs

@@ -3,6 +3,10 @@ use butane::prelude::*;
 use butane::{butane_type, find, model, query};
 use butane::{ForeignKey, ObjectState};
 use paste;
+#[cfg(feature = "pg")]
+use postgres;
+#[cfg(feature = "sqlite")]
+use rusqlite;
 
 mod common;
 
@@ -13,6 +17,7 @@ pub type Whatsit = String;
 #[derive(PartialEq, Eq, Debug, Clone)]
 struct Foo {
     id: i64,
+    #[unique]
     bar: u32,
     baz: Whatsit,
     blobbity: Vec<u8>,
@@ -263,3 +268,27 @@ fn basic_rollback_transaction(mut conn: Connection) {
     }
 }
 testall!(basic_rollback_transaction);
+
+fn basic_unique_field_error_on_non_unique(conn: Connection) {
+    let mut foo1 = Foo::new(1);
+    foo1.bar = 42;
+    foo1.save(&conn).unwrap();
+
+    let mut foo2 = Foo::new(2);
+    foo2.bar = foo1.bar;
+    let e = foo2.save(&conn).unwrap_err();
+    // Make sure the error is one we expect
+    assert!(match e {
+        #[cfg(feature = "sqlite")]
+        butane::Error::SQLite(rusqlite::Error::SqliteFailure(
+            rusqlite::ffi::Error { code, .. },
+            _,
+        )) if code == rusqlite::ffi::ErrorCode::ConstraintViolation => true,
+        #[cfg(feature = "pg")]
+        butane::Error::Postgres(e)
+            if e.code() == Some(&postgres::error::SqlState::UNIQUE_VIOLATION) =>
+            true,
+        _ => false,
+    });
+}
+testall!(basic_unique_field_error_on_non_unique);

butane_cli/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "butane_cli"
-version = "0.3.0"
+version = "0.3.1"
 authors = ["James Oakley <[email protected]>"]
 edition = "2018"
 description = "The CLI for the Butane ORM"
@@ -15,7 +15,7 @@ path = "src/main.rs"
 
 [dependencies]
 anyhow = "1.0"
-butane = { path="../butane", version="0.3", features=["default", "sqlite", "pg"] }
+butane = { path="../butane", version="0.3.1", features=["default", "sqlite", "pg"] }
 chrono = "0.4"
 clap = "2.33"
 quote = "1.0"

butane_codegen/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "butane_codegen"
-version = "0.3.0"
+version = "0.3.1"
 authors = ["James Oakley <[email protected]>"]
 edition = "2018"
 description = "Macros for Butane. Do not use this crate directly -- use the butane crate."
@@ -13,7 +13,7 @@ datetime = []
 
 [dependencies]
 proc-macro2 = "1.0"
-butane_core = { path = "../butane_core", version = "0.3.0" }
+butane_core = { path = "../butane_core", version = "0.3.1" }
 quote = "1.0"
 syn = { version = "1.0", features = ["full", "extra-traits"] }
 uuid = {version = "0.8", optional=true}

butane_codegen/src/lib.rs

@@ -29,6 +29,8 @@ mod filter;
 ///    initialized based on serial/autoincrement. Currently supported
 ///    only on the primary key and only if the primary key is an integer
 ///    type
+/// * `#[unique]` on a field indicates that the field's value must be unique
+///    (perhaps implemented as the SQL UNIQUE constraint by some backends).
 /// * `[default]` should be used on fields added by later migrations to avoid errors on existing objects.
 ///     Unnecessary if the new field is an `Option<>`
 ///

butane_core/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "butane_core"
-version = "0.3.0"
+version = "0.3.1"
 authors = ["James Oakley <[email protected]>"]
 edition = "2018"
 description = "Internals for Butane. Do not use this crate directly -- use the butane crate."

butane_core/src/codegen/migration.rs

@@ -49,6 +49,7 @@ fn create_atables(ast_struct: &ItemStruct, config: &dbobj::Config) -> Vec<ATable
                 is_nullable(&f),
                 f == &pk,
                 is_auto(&f),
+                is_unique(&f),
                 get_default(&f).expect("Malformed default attribute"),
             );
             table.add_column(col);

butane_core/src/codegen/mod.rs

@@ -242,6 +242,7 @@ fn remove_helper_field_attributes(
                         && !a.path.is_ident("auto")
                         && !a.path.is_ident("sqltype")
                         && !a.path.is_ident("default")
+                        && !a.path.is_ident("unique")
                 });
             }
             Ok(fields)
@@ -289,6 +290,10 @@ fn is_auto(field: &Field) -> bool {
     field.attrs.iter().any(|attr| attr.path.is_ident("auto"))
 }
 
+fn is_unique(field: &Field) -> bool {
+    field.attrs.iter().any(|attr| attr.path.is_ident("unique"))
+}
+
 fn fields(ast_struct: &ItemStruct) -> impl Iterator<Item = &Field> {
     ast_struct
         .fields

butane_core/src/db/pg.rs

@@ -538,6 +538,9 @@ fn define_column(col: &AColumn) -> Result<String> {
     if col.is_pk() {
         constraints.push("PRIMARY KEY".to_string());
     }
+    if col.unique() {
+        constraints.push("UNIQUE".to_string());
+    }
     Ok(format!(
         "{} {} {}",
         &col.name(),

butane_core/src/db/sqlite.rs

@@ -462,6 +462,9 @@ fn define_column(col: &AColumn) -> String {
         // and we only allow auto on integer types
         constraints.push("AUTOINCREMENT".to_string());
     }
+    if col.unique() {
+        constraints.push("UNIQUE".to_string());
+    }
     format!(
         "{} {} {}",
         &col.name(),

butane_core/src/migrations/adb.rs

@@ -309,6 +309,8 @@ pub struct AColumn {
     nullable: bool,
     pk: bool,
     auto: bool,
+    #[serde(default)]
+    unique: bool,
     default: Option<SqlVal>,
 }
 impl AColumn {
@@ -318,6 +320,7 @@ impl AColumn {
         nullable: bool,
         pk: bool,
         auto: bool,
+        unique: bool,
         default: Option<SqlVal>,
     ) -> Self {
         AColumn {
@@ -326,19 +329,23 @@ impl AColumn {
             nullable,
             pk,
             auto,
+            unique,
             default,
         }
     }
-    /// Simple column that is non-null, non-auto, non-pk with no default
+    /// Simple column that is non-null, non-auto, non-pk, non-unique with no default
     pub fn new_simple(name: impl Into<String>, sqltype: DeferredSqlType) -> Self {
-        Self::new(name, sqltype, false, false, false, None)
+        Self::new(name, sqltype, false, false, false, false, None)
     }
     pub fn name(&self) -> &str {
         &self.name
     }
     pub fn nullable(&self) -> bool {
         self.nullable
     }
+    pub fn unique(&self) -> bool {
+        self.unique
+    }
     pub fn is_pk(&self) -> bool {
         self.pk
     }

butane_core/src/migrations/mod.rs

@@ -168,6 +168,7 @@ fn migrations_table() -> ATable {
         false, // nullable
         true,  // pk
         false, // auto
+        false, // unique
         None,
     );
     table.add_column(col);

examples/getting_started/.butane/migrations/current/Blog.table

@@ -1 +1 @@
-{"name":"Blog","columns":[{"name":"id","sqltype":{"KnownId":{"Ty":"BigInt"}},"nullable":false,"pk":true,"auto":true,"default":null},{"name":"name","sqltype":{"KnownId":{"Ty":"Text"}},"nullable":false,"pk":false,"auto":false,"default":null}]}
+{"name":"Blog","columns":[{"name":"id","sqltype":{"KnownId":{"Ty":"BigInt"}},"nullable":false,"pk":true,"auto":true,"unique":false,"default":null},{"name":"name","sqltype":{"KnownId":{"Ty":"Text"}},"nullable":false,"pk":false,"auto":false,"unique":false,"default":null}]}

examples/getting_started/.butane/migrations/current/Post.table

@@ -1 +1 @@
-{"name":"Post","columns":[{"name":"id","sqltype":{"KnownId":{"Ty":"Int"}},"nullable":false,"pk":true,"auto":true,"default":null},{"name":"title","sqltype":{"KnownId":{"Ty":"Text"}},"nullable":false,"pk":false,"auto":false,"default":null},{"name":"body","sqltype":{"KnownId":{"Ty":"Text"}},"nullable":false,"pk":false,"auto":false,"default":null},{"name":"published","sqltype":{"KnownId":{"Ty":"Bool"}},"nullable":false,"pk":false,"auto":false,"default":null},{"name":"blog","sqltype":{"Deferred":"PK:Blog"},"nullable":false,"pk":false,"auto":false,"default":null},{"name":"byline","sqltype":{"KnownId":{"Ty":"Text"}},"nullable":true,"pk":false,"auto":false,"default":null},{"name":"likes","sqltype":{"KnownId":{"Ty":"Int"}},"nullable":false,"pk":false,"auto":false,"default":null}]}
+{"name":"Post","columns":[{"name":"id","sqltype":{"KnownId":{"Ty":"Int"}},"nullable":false,"pk":true,"auto":true,"unique":false,"default":null},{"name":"title","sqltype":{"KnownId":{"Ty":"Text"}},"nullable":false,"pk":false,"auto":false,"unique":false,"default":null},{"name":"body","sqltype":{"KnownId":{"Ty":"Text"}},"nullable":false,"pk":false,"auto":false,"unique":false,"default":null},{"name":"published","sqltype":{"KnownId":{"Ty":"Bool"}},"nullable":false,"pk":false,"auto":false,"unique":false,"default":null},{"name":"blog","sqltype":{"Deferred":"PK:Blog"},"nullable":false,"pk":false,"auto":false,"unique":false,"default":null},{"name":"byline","sqltype":{"KnownId":{"Ty":"Text"}},"nullable":true,"pk":false,"auto":false,"unique":false,"default":null},{"name":"likes","sqltype":{"KnownId":{"Ty":"Int"}},"nullable":false,"pk":false,"auto":false,"unique":false,"default":null}]}

examples/getting_started/.butane/migrations/current/Post_tags_Many.table

@@ -1 +1 @@
-{"name":"Post_tags_Many","columns":[{"name":"owner","sqltype":{"KnownId":{"Ty":"Int"}},"nullable":false,"pk":false,"auto":false,"default":null},{"name":"has","sqltype":{"Deferred":"PK:Tag"},"nullable":false,"pk":false,"auto":false,"default":null}]}
+{"name":"Post_tags_Many","columns":[{"name":"owner","sqltype":{"KnownId":{"Ty":"Int"}},"nullable":false,"pk":false,"auto":false,"unique":false,"default":null},{"name":"has","sqltype":{"Deferred":"PK:Tag"},"nullable":false,"pk":false,"auto":false,"unique":false,"default":null}]}

examples/getting_started/.butane/migrations/current/Tag.table

@@ -1 +1 @@
-{"name":"Tag","columns":[{"name":"tag","sqltype":{"KnownId":{"Ty":"Text"}},"nullable":false,"pk":true,"auto":false,"default":null}]}
+{"name":"Tag","columns":[{"name":"tag","sqltype":{"KnownId":{"Ty":"Text"}},"nullable":false,"pk":true,"auto":false,"unique":false,"default":null}]}