Merge pull request diesel-rs#1033 from alexcameron89/add_citext_type

Add support for Citext Postgres Type

Author: alexcameron89

diesel/src/pg/types/mod.rs

@@ -95,6 +95,9 @@ pub mod sql_types {
     #[doc(hidden)]
     pub type Bpchar = ::types::VarChar;
 
+    #[doc(hidden)]
+    pub type Citext = ::types::Text;
+
     #[cfg(feature = "serde_json")]
     /// The JSON SQL type.  This type can only be used with `feature =
     /// "serde_json"`

diesel_infer_schema/src/pg.rs

@@ -11,12 +11,15 @@ pub fn determine_column_type(attr: &ColumnInformation) -> Result<ColumnType, Box
         &attr.type_name
     };
 
-    let tpe_is_varchar = tpe.to_lowercase() == "varchar";
+    let diesel_alias_without_postgres_coercion = match &*tpe.to_lowercase() {
+        "varchar" | "citext" => Some(tpe),
+        _ => None,
+    };
 
     // Postgres doesn't coerce varchar[] to text[] so print out a message to inform
     // the user.
-    if tpe_is_varchar && is_array {
-        writeln!(&mut stderr(), "The column `{}` is of type `varchar[]`. This will cause problems when using Diesel. You should consider changing the column type to `text[]`.", attr.column_name)?;
+    if let (true, Some(tpe)) = (is_array, diesel_alias_without_postgres_coercion) {
+        writeln!(&mut stderr(), "The column `{}` is of type `{}[]`. This will cause problems when using Diesel. You should consider changing the column type to `text[]`.", attr.column_name, tpe)?;
     }
 
     Ok(ColumnType {

diesel_tests/tests/lib.rs

@@ -28,6 +28,8 @@ mod joins;
 mod macros;
 mod order;
 mod perf_details;
+#[cfg(feature = "postgres")]
+mod postgres_types;
 mod schema;
 mod schema_dsl;
 mod schema_inference;

diesel_tests/tests/postgres_types.rs

@@ -0,0 +1,18 @@
+use schema::*;
+use diesel::*;
+
+#[test]
+fn ci_text_exists_and_coerces_from_text() {
+    use schema::citext_table::dsl::*;
+
+    let conn = connection();
+    conn.execute("INSERT INTO citext_table (citext_field) VALUES ('foo'::citext), ('bar'::citext)")
+        .unwrap();
+    let data = citext_table
+        .filter(citext_field.eq("foo"))
+        .select(citext_field)
+        .load::<String>(&conn);
+    let expected = vec!["foo".into()];
+
+    assert_eq!(Ok(expected), data);
+}

migrations/postgresql/20170721184144_create_citext_table/down.sql

@@ -0,0 +1 @@
+DROP TABLE citext_table;

migrations/postgresql/20170721184144_create_citext_table/up.sql

@@ -0,0 +1,2 @@
+CREATE EXTENSION IF NOT EXISTS citext;
+CREATE TABLE citext_table (citext_field CITEXT PRIMARY KEY);