Add a generic cargo feature flag for generic SQL connection.

crates/sqlite/Cargo.toml

@@ -21,6 +21,7 @@ harness = false
 
 [features]
 default = ["pg"]
+generic = ["pg"]
 pg = ["dep:postgres", "dep:bytes", "dep:pgrow2serde", "dep:regex"]
 
 [dependencies]

crates/sqlite/src/connection.rs

@@ -1,3 +0,0 @@
-pub use crate::sqlite::connection::{ArcLockGuard, Connection, LockError, LockGuard, Options};
-pub use crate::sqlite::sync::SyncConnection;
-pub use crate::traits::SyncConnection as SyncConnectionTrait;

crates/sqlite/src/generic.rs

@@ -54,6 +54,21 @@ impl Connection {
     });
   }
 
+  pub fn open_in_memory() -> Result<Self, Error> {
+    return Self::new(|| -> Result<_, Error> {
+      let exec = crate::sqlite::executor::Executor::new(
+        rusqlite::Connection::open_in_memory,
+        crate::sqlite::executor::Options {
+          num_threads: Some(1),
+          ..Default::default()
+        },
+      )?;
+      assert_eq!(1, exec.threads());
+
+      return Ok(Executor::Sqlite(exec));
+    });
+  }
+
   pub fn id(&self) -> usize {
     return self.id;
   }

crates/sqlite/src/lib.rs

@@ -10,11 +10,9 @@
   clippy::needless_continue
 )]
 
-mod connection;
 mod database;
 mod error;
 pub mod from_sql;
-mod generic;
 mod params;
 mod rows;
 pub mod sqlite;
@@ -23,18 +21,32 @@ pub mod to_sql;
 pub mod traits;
 mod value;
 
+#[cfg(feature = "pg")]
+mod generic;
 #[cfg(feature = "pg")]
 mod pg;
 
-pub use connection::{
-  ArcLockGuard, Connection, LockError, LockGuard, Options, SyncConnection, SyncConnectionTrait,
-};
+#[cfg(not(feature = "generic"))]
+mod connection_imports {
+  pub use super::sqlite::connection::{ArcLockGuard, Connection, LockError, LockGuard, Options};
+  pub use super::sqlite::sync::SyncConnection;
+}
+
+#[cfg(feature = "generic")]
+mod connection_imports {
+  pub use super::generic::{Connection, SyncConnection};
+  pub use super::sqlite::connection::{ArcLockGuard, LockError, LockGuard, Options};
+}
+
+pub use connection_imports::*;
+
 pub use database::Database;
 pub use error::Error;
 pub use params::{NamedParamRef, NamedParams, NamedParamsRef, Params};
 pub use rows::{Row, Rows, ValueType};
 pub use sqlite::transaction::Transaction;
 pub use statement::Statement;
+pub use traits::SyncConnection as SyncConnectionTrait;
 pub use value::{Value, ValueRef};
 
 #[macro_export]

crates/sqlite/src/sqlite/batch.rs

@@ -2,9 +2,9 @@ use rusqlite::fallible_iterator::FallibleIterator;
 use std::sync::Arc;
 
 use super::util::{columns, from_row};
-use crate::connection::Connection;
 use crate::error::Error;
 use crate::rows::{Column, Rows};
+use crate::sqlite::connection::Connection;
 
 /// Batch execute SQL statements and return rows of last statement.
 ///

crates/sqlite/src/tests.rs

@@ -4,7 +4,7 @@ use rusqlite::{ErrorCode, ffi};
 use serde::Deserialize;
 use std::borrow::Cow;
 
-use crate::connection::{Connection, Options};
+use crate::sqlite::connection::{Connection, Options};
 use crate::sqlite::extract_row_id;
 use crate::{Database, Error, SyncConnectionTrait, Value, ValueType};