jasonlin45 commented on code in PR #3325: URL: https://github.com/apache/arrow-adbc/pull/3325#discussion_r2330685733
########## go/adbc/driver/databricks/connection.go: ########## @@ -0,0 +1,290 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +package databricks + +import ( + "context" + "database/sql" + "fmt" + + "github.com/apache/arrow-adbc/go/adbc" + "github.com/apache/arrow-adbc/go/adbc/driver/internal/driverbase" + "github.com/apache/arrow-go/v18/arrow" + "github.com/apache/arrow-go/v18/arrow/array" + "github.com/apache/arrow-go/v18/arrow/memory" + _ "github.com/databricks/databricks-sql-go" +) + +type connectionImpl struct { + driverbase.ConnectionImplBase + + // Connection settings + catalog string + dbSchema string + + // Database connection + conn *sql.Conn +} + +func (c *connectionImpl) Close() error { + if c.conn == nil { + return adbc.Error{Code: adbc.StatusInvalidState} + } + defer func() { + c.conn = nil + }() + return c.conn.Close() +} + +func (c *connectionImpl) NewStatement() (adbc.Statement, error) { + return &statementImpl{ + conn: c, + }, nil +} + +// Autocommit interface implementation +func (c *connectionImpl) GetAutocommit() bool { + // Databricks SQL doesn't support explicit transaction control in the same way + // as traditional databases. Most operations are implicitly committed. + return true +} + +func (c *connectionImpl) SetAutocommit(autocommit bool) error { + // Databricks SQL doesn't support explicit transaction control in the same way + // as traditional databases. Most operations are implicitly committed. + if !autocommit { + return adbc.Error{ + Code: adbc.StatusNotImplemented, + Msg: fmt.Sprintf("disabling autocommit is not supported"), + } + } else { + return nil + } +} + +// CurrentNamespacer interface implementation +func (c *connectionImpl) GetCurrentCatalog() (string, error) { + return c.catalog, nil +} + +func (c *connectionImpl) GetCurrentDbSchema() (string, error) { + return c.dbSchema, nil +} + +func (c *connectionImpl) SetCurrentCatalog(catalog string) error { + // Use the database to execute USE CATALOG + if c.conn != nil && catalog != "" { + _, err := c.conn.ExecContext(context.TODO(), "USE CATALOG `%s`", catalog) + if err != nil { + return adbc.Error{ + Code: adbc.StatusInternal, + Msg: fmt.Sprintf("failed to set catalog: %v", err), + } + } + } + c.catalog = catalog + return nil +} + +func (c *connectionImpl) SetCurrentDbSchema(schema string) error { + // Use the database to execute USE SCHEMA + if c.conn != nil && schema != "" { + _, err := c.conn.ExecContext(context.TODO(), "USE SCHEMA `%s`", schema) + if err != nil { + return adbc.Error{ + Code: adbc.StatusInternal, + Msg: fmt.Sprintf("failed to set schema: %v", err), + } + } + } + c.dbSchema = schema + return nil +} + +// TableTypeLister interface implementation +func (c *connectionImpl) ListTableTypes(ctx context.Context) ([]string, error) { + // Databricks supports these table types + return []string{"TABLE", "VIEW", "EXTERNAL_TABLE", "MANAGED_TABLE"}, nil +} + +func (c *connectionImpl) GetTableTypes(ctx context.Context) (array.RecordReader, error) { + // Databricks supports these table types + tableTypes := []string{"TABLE", "VIEW", "EXTERNAL_TABLE", "MANAGED_TABLE"} + + // Create Arrow schema for table types + schema := arrow.NewSchema([]arrow.Field{ + {Name: "table_type", Type: arrow.BinaryTypes.String}, + }, nil) + + // Create record batch + bldr := array.NewRecordBuilder(memory.DefaultAllocator, schema) + defer bldr.Release() + + tableTypeBuilder := bldr.Field(0).(*array.StringBuilder) + for _, tableType := range tableTypes { + tableTypeBuilder.Append(tableType) + } + + rec := bldr.NewRecord() + defer rec.Release() + + reader, err := array.NewRecordReader(schema, []arrow.Record{rec}) + if err != nil { + return nil, err + } + return reader, nil +} + +// Transaction methods (Databricks has limited transaction support) +func (c *connectionImpl) Commit(ctx context.Context) error { + // Most operations are auto-committed. + return nil +} + +func (c *connectionImpl) Rollback(ctx context.Context) error { + // Databricks SQL doesn't support explicit transactions in the traditional sense. + // Most operations are auto-committed. We'll track state but not perform any operation. + return adbc.Error{ + Code: adbc.StatusNotImplemented, + Msg: fmt.Sprintf("rollback is not supported"), + } +} + +// DbObjectsEnumerator interface implementation +func (c *connectionImpl) GetCatalogs(ctx context.Context, catalogFilter *string) ([]string, error) { + query := "SHOW CATALOGS" + if catalogFilter != nil { + query += fmt.Sprintf(" LIKE '%s'", *catalogFilter) + } + + rows, err := c.conn.QueryContext(ctx, query) + if err != nil { + return nil, adbc.Error{ + Code: adbc.StatusInternal, + Msg: fmt.Sprintf("failed to query catalogs: %v", err), + } + } + defer func() { _ = rows.Close() }() + + var catalogs []string + for rows.Next() { + var catalog string + if err := rows.Scan(&catalog); err != nil { + return nil, adbc.Error{ + Code: adbc.StatusInternal, + Msg: fmt.Sprintf("failed to scan catalog: %v", err), + } + } + catalogs = append(catalogs, catalog) + } + + return catalogs, rows.Err() +} + +func (c *connectionImpl) GetDBSchemasForCatalog(ctx context.Context, catalog string, schemaFilter *string) ([]string, error) { + query := fmt.Sprintf("SHOW SCHEMAS IN `%s`", catalog) + if schemaFilter != nil { + query += fmt.Sprintf(" LIKE '%s'", *schemaFilter) + } + + rows, err := c.conn.QueryContext(ctx, query) + if err != nil { + return nil, adbc.Error{ + Code: adbc.StatusInternal, + Msg: fmt.Sprintf("failed to query schemas: %v", err), + } + } + defer func() { _ = rows.Close() }() Review Comment: Of course. Thank you for pointing to `errors.Join`, I am a GoLang newbie, so appreciate that tip a lot! Updated in 08478ec88 -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: github-unsubscr...@arrow.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
