feat(sql-catalog): implement register table for sql catalog (#1724)

## Which issue does this PR close?



- Closes #1518.

## What changes are included in this PR?



- Implement `register_table` for sql catalog

## Are these changes tested?



---------

Signed-off-by: Alan Tang <[email protected]>

Author: Standing-Man

crates/catalog/sql/src/catalog.rs

@@ -765,13 +765,30 @@ impl Catalog for SqlCatalog {
 
     async fn register_table(
         &self,
-        _table_ident: &TableIdent,
-        _metadata_location: String,
+        table_ident: &TableIdent,
+        metadata_location: String,
     ) -> Result<Table> {
-        Err(Error::new(
-            ErrorKind::FeatureUnsupported,
-            "Registering a table is not supported yet",
-        ))
+        if self.table_exists(table_ident).await? {
+            return table_already_exists_err(table_ident);
+        }
+
+        let metadata = TableMetadata::read_from(&self.fileio, &metadata_location).await?;
+
+        let namespace = table_ident.namespace();
+        let tbl_name = table_ident.name().to_string();
+
+        self.execute(&format!(
+            "INSERT INTO {CATALOG_TABLE_NAME}
+             ({CATALOG_FIELD_CATALOG_NAME}, {CATALOG_FIELD_TABLE_NAMESPACE}, {CATALOG_FIELD_TABLE_NAME}, {CATALOG_FIELD_METADATA_LOCATION_PROP}, {CATALOG_FIELD_RECORD_TYPE})
+             VALUES (?, ?, ?, ?, ?)
+            "), vec![Some(&self.name), Some(&namespace.join(".")), Some(&tbl_name), Some(&metadata_location), Some(CATALOG_FIELD_TABLE_RECORD_TYPE)], None).await?;
+
+        Ok(Table::builder()
+            .identifier(table_ident.clone())
+            .metadata_location(metadata_location)
+            .metadata(metadata)
+            .file_io(self.fileio.clone())
+            .build()?)
     }
 
     async fn update_table(&self, _commit: TableCommit) -> Result<Table> {
@@ -1908,4 +1925,63 @@ mod tests {
             "Unexpected => No such table: TableIdent { namespace: NamespaceIdent([\"a\"]), name: \"tbl1\" }"
         );
     }
+
+    #[tokio::test]
+    async fn test_register_table_throws_error_if_table_with_same_name_already_exists() {
+        let warehouse_loc = temp_path();
+        let catalog = new_sql_catalog(warehouse_loc.clone()).await;
+        let namespace_ident = NamespaceIdent::new("a".into());
+        create_namespace(&catalog, &namespace_ident).await;
+        let table_name = "tbl1";
+        let table_ident = TableIdent::new(namespace_ident.clone(), table_name.into());
+        create_table(&catalog, &table_ident).await;
+
+        assert_eq!(
+            catalog
+                .register_table(&table_ident, warehouse_loc)
+                .await
+                .unwrap_err()
+                .to_string(),
+            format!("Unexpected => Table {:?} already exists.", &table_ident)
+        );
+    }
+
+    #[tokio::test]
+    async fn test_register_table() {
+        let warehouse_loc = temp_path();
+        let catalog = new_sql_catalog(warehouse_loc.clone()).await;
+        let namespace_ident = NamespaceIdent::new("a".into());
+        create_namespace(&catalog, &namespace_ident).await;
+
+        let table_name = "abc";
+        let location = warehouse_loc.clone();
+        let table_creation = TableCreation::builder()
+            .name(table_name.into())
+            .location(location.clone())
+            .schema(simple_table_schema())
+            .build();
+
+        let table_ident = TableIdent::new(namespace_ident.clone(), table_name.into());
+        let expected_table = catalog
+            .create_table(&namespace_ident, table_creation)
+            .await
+            .unwrap();
+
+        let metadata_location = expected_table
+            .metadata_location()
+            .expect("Expected metadata location to be set")
+            .to_string();
+
+        assert_table_eq(&expected_table, &table_ident, &simple_table_schema());
+
+        let _ = catalog.drop_table(&table_ident).await;
+
+        let table = catalog
+            .register_table(&table_ident, metadata_location.clone())
+            .await
+            .unwrap();
+
+        assert_eq!(table.identifier(), expected_table.identifier());
+        assert_eq!(table.metadata_location(), Some(metadata_location.as_str()));
+    }
 }