Fix the information_schema queries.

driver/connection.go

@@ -1,13 +1,14 @@
 package driver
 
 import (
-	"cloud.google.com/go/bigquery"
 	"context"
 	"database/sql/driver"
 	"fmt"
+
+	"cloud.google.com/go/bigquery"
 )
 
-type bigQueryConnection struct {
+type BigQueryConnection struct {
 	ctx     context.Context
 	client  *bigquery.Client
 	config  bigQueryConfig
@@ -16,19 +17,19 @@ type bigQueryConnection struct {
 	dataset *bigquery.Dataset
 }
 
-func (connection *bigQueryConnection) GetDataset() *bigquery.Dataset {
+func (connection *BigQueryConnection) GetDataset() *bigquery.Dataset {
 	if connection.dataset != nil {
 		return connection.dataset
 	}
 	connection.dataset = connection.client.Dataset(connection.config.dataSet)
 	return connection.dataset
 }
 
-func (connection *bigQueryConnection) GetContext() context.Context {
+func (connection *BigQueryConnection) GetContext() context.Context {
 	return connection.ctx
 }
 
-func (connection *bigQueryConnection) Ping(ctx context.Context) error {
+func (connection *BigQueryConnection) Ping(ctx context.Context) error {
 
 	dataset := connection.GetDataset()
 	if dataset == nil {
@@ -43,12 +44,12 @@ func (connection *bigQueryConnection) Ping(ctx context.Context) error {
 	return nil
 }
 
-func (connection *bigQueryConnection) QueryContext(ctx context.Context, query string, args []driver.NamedValue) (driver.Rows, error) {
+func (connection *BigQueryConnection) QueryContext(ctx context.Context, query string, args []driver.NamedValue) (driver.Rows, error) {
 	var statement = &bigQueryStatement{connection, query}
 	return statement.QueryContext(ctx, args)
 }
 
-func (connection *bigQueryConnection) Query(query string, args []driver.Value) (driver.Rows, error) {
+func (connection *BigQueryConnection) Query(query string, args []driver.Value) (driver.Rows, error) {
 	statement, err := connection.Prepare(query)
 	if err != nil {
 		return nil, nil
@@ -57,13 +58,13 @@ func (connection *bigQueryConnection) Query(query string, args []driver.Value) (
 	return statement.Query(args)
 }
 
-func (connection *bigQueryConnection) Prepare(query string) (driver.Stmt, error) {
+func (connection *BigQueryConnection) Prepare(query string) (driver.Stmt, error) {
 	var statement = &bigQueryStatement{connection, query}
 
 	return statement, nil
 }
 
-func (connection *bigQueryConnection) Close() error {
+func (connection *BigQueryConnection) Close() error {
 	if connection.closed {
 		return nil
 	}
@@ -74,27 +75,27 @@ func (connection *bigQueryConnection) Close() error {
 	return connection.client.Close()
 }
 
-func (connection *bigQueryConnection) Begin() (driver.Tx, error) {
+func (connection *BigQueryConnection) Begin() (driver.Tx, error) {
 	var transaction = &bigQueryTransaction{connection}
 
 	return transaction, nil
 }
 
-func (connection *bigQueryConnection) query(query string) (*bigquery.Query, error) {
+func (connection *BigQueryConnection) query(query string) (*bigquery.Query, error) {
 	return connection.client.Query(query), nil
 }
 
-func (connection *bigQueryConnection) ExecContext(ctx context.Context, query string, args []driver.NamedValue) (driver.Result, error) {
+func (connection *BigQueryConnection) ExecContext(ctx context.Context, query string, args []driver.NamedValue) (driver.Result, error) {
 	var statement = &bigQueryStatement{connection, query}
 	return statement.ExecContext(ctx, args)
 }
 
-func (connection *bigQueryConnection) Exec(query string, args []driver.Value) (driver.Result, error) {
+func (connection *BigQueryConnection) Exec(query string, args []driver.Value) (driver.Result, error) {
 	var statement = &bigQueryStatement{connection, query}
 	return statement.Exec(args)
 }
 
-func (bigQueryConnection) CheckNamedValue(*driver.NamedValue) error {
+func (BigQueryConnection) CheckNamedValue(*driver.NamedValue) error {
 	// TODO: Revise in the future
 	return nil
 }

driver/driver.go

@@ -57,7 +57,7 @@ func (b bigQueryDriver) Open(uri string) (driver.Conn, error) {
 		return nil, err
 	}
 
-	return &bigQueryConnection{
+	return &BigQueryConnection{
 		ctx:    ctx,
 		client: client,
 		config: *config,

driver/statement.go

@@ -1,16 +1,17 @@
 package driver
 
 import (
-	"cloud.google.com/go/bigquery"
 	"context"
 	"database/sql/driver"
 	"errors"
+
+	"cloud.google.com/go/bigquery"
 	"github.com/sirupsen/logrus"
 	"gorm.io/driver/bigquery/adaptor"
 )
 
 type bigQueryStatement struct {
-	connection *bigQueryConnection
+	connection *BigQueryConnection
 	query      string
 }
 

driver/transaction.go

@@ -1,7 +1,7 @@
 package driver
 
 type bigQueryTransaction struct {
-	connection *bigQueryConnection
+	connection *BigQueryConnection
 }
 
 func (transaction *bigQueryTransaction) Commit() error {

migrator.go

@@ -1,9 +1,16 @@
 package bigquery
 
 import (
+	"context"
 	"errors"
+	"fmt"
+	"slices"
+	"strings"
+
+	"gorm.io/driver/bigquery/driver"
 	"gorm.io/gorm"
 	"gorm.io/gorm/clause"
+	"gorm.io/gorm/logger"
 	"gorm.io/gorm/migrator"
 	"gorm.io/gorm/schema"
 )
@@ -13,8 +20,11 @@ type Migrator struct {
 }
 
 func (m Migrator) CurrentDatabase() (name string) {
-	m.DB.Raw("SELECT CURRENT_DATABASE()").Row().Scan(&name)
-	return
+	datasetID, err := m.getDatasetID()
+	if err != nil {
+		return ""
+	}
+	return datasetID
 }
 
 func (m Migrator) BuildIndexOptions(opts []schema.IndexOption, stmt *gorm.Statement) (results []interface{}) {
@@ -40,7 +50,15 @@ func (m Migrator) DropIndex(value interface{}, name string) error {
 func (m Migrator) HasTable(value interface{}) bool {
 	var count int64
 	m.RunWithValue(value, func(stmt *gorm.Statement) error {
-		return m.DB.Raw("SELECT count(*) FROM `INFORMATION_SCHEMA.TABLES` WHERE table_name = ?", stmt.Table).Row().Scan(&count)
+		// According to the BigQuery documentation, an INFORMATION_SCHEMA view must be qualified with a dataset or region.
+		// See: https://docs.cloud.google.com/bigquery/docs/information-schema-intro
+		//
+		// We are going to attempt to get the dataset ID from the connection and use it to qualify the INFORMATION_SCHEMA view.
+		datasetID, err := m.getDatasetID()
+		if err != nil {
+			return err
+		}
+		return m.DB.Raw("SELECT count(*) FROM `"+datasetID+".INFORMATION_SCHEMA.TABLES` WHERE table_name = ?", stmt.Table).Row().Scan(&count)
 	})
 
 	return count > 0
@@ -67,8 +85,17 @@ func (m Migrator) HasColumn(value interface{}, field string) bool {
 			name = field.DBName
 		}
 
+		// According to the BigQuery documentation, an INFORMATION_SCHEMA view must be qualified with a dataset or region.
+		// See: https://docs.cloud.google.com/bigquery/docs/information-schema-intro
+		//
+		// We are going to attempt to get the dataset ID from the connection and use it to qualify the INFORMATION_SCHEMA view.
+		datasetID, err := m.getDatasetID()
+		if err != nil {
+			return err
+		}
+
 		return m.DB.Raw(
-			"SELECT count(*) FROM INFORMATION_SCHEMA.columns WHERE table_schema = CURRENT_SCHEMA() AND table_name = ? AND column_name = ?",
+			"SELECT count(*) FROM `"+datasetID+".INFORMATION_SCHEMA.columns` WHERE table_schema = CURRENT_SCHEMA() AND table_name = ? AND column_name = ?",
 			stmt.Table, name,
 		).Row().Scan(&count)
 	})
@@ -79,11 +106,87 @@ func (m Migrator) HasColumn(value interface{}, field string) bool {
 func (m Migrator) HasConstraint(value interface{}, name string) bool {
 	var count int64
 	m.RunWithValue(value, func(stmt *gorm.Statement) error {
+		// According to the BigQuery documentation, an INFORMATION_SCHEMA view must be qualified with a dataset or region.
+		// See: https://docs.cloud.google.com/bigquery/docs/information-schema-intro
+		//
+		// We are going to attempt to get the dataset ID from the connection and use it to qualify the INFORMATION_SCHEMA view.
+		datasetID, err := m.getDatasetID()
+		if err != nil {
+			return err
+		}
+
 		return m.DB.Raw(
-			"SELECT count(*) FROM INFORMATION_SCHEMA.table_constraints WHERE table_schema = CURRENT_SCHEMA() AND table_name = ? AND constraint_name = ?",
+			"SELECT count(*) FROM `"+datasetID+".INFORMATION_SCHEMA.table_constraints` WHERE table_schema = CURRENT_SCHEMA() AND table_name = ? AND constraint_name = ?",
 			stmt.Table, name,
 		).Row().Scan(&count)
 	})
 
 	return count > 0
 }
+
+// FullDataTypeOf returns field's db full data type
+func (m Migrator) FullDataTypeOf(field *schema.Field) (expr clause.Expr) {
+	expr.SQL = m.DataTypeOf(field)
+
+	if field.NotNull {
+		expr.SQL += " NOT NULL"
+	}
+
+	if field.HasDefaultValue && (field.DefaultValueInterface != nil || field.DefaultValue != "") {
+		if field.DefaultValueInterface != nil {
+			defaultStmt := &gorm.Statement{Vars: []interface{}{field.DefaultValueInterface}}
+			m.Dialector.BindVarTo(defaultStmt, defaultStmt, field.DefaultValueInterface)
+			expr.SQL += " DEFAULT " + m.Dialector.Explain(defaultStmt.SQL.String(), field.DefaultValueInterface)
+		} else if field.DefaultValue != "(-)" {
+			expr.SQL += " DEFAULT " + field.DefaultValue
+		}
+	}
+
+	options := map[string]string{}
+	if field.Comment != "" {
+		options["description"] = field.Comment
+	}
+
+	if len(options) > 0 {
+		optionParts := []string{}
+		for key, value := range options {
+			optionParts = append(optionParts, fmt.Sprintf("%s = %s", key, logger.ExplainSQL("?", nil, `'`, value)))
+		}
+		slices.Sort(optionParts)
+		expr.SQL += " OPTIONS (" + strings.Join(optionParts, ", ") + ")"
+	}
+
+	return
+}
+
+// getDatasetID is a helper function to get the dataset ID from the connection.
+func (m Migrator) getDatasetID() (string, error) {
+	sqlDB, err := m.DB.DB()
+	if err != nil {
+		return "", fmt.Errorf("could not get underlying database: %w", err)
+	}
+	ctx := context.Background()
+	conn, err := sqlDB.Conn(ctx)
+	if err != nil {
+		return "", fmt.Errorf("could not get connection: %w", err)
+	}
+
+	datasetID := ""
+	err = conn.Raw(func(rawConnection any) error {
+		bigQueryConnection, ok := rawConnection.(*driver.BigQueryConnection)
+		if !ok {
+			return errors.New("connection is not a *driver.BigQueryConnection")
+		}
+		dataset := bigQueryConnection.GetDataset()
+		if dataset == nil {
+			return errors.New("dataset is nil")
+		}
+		datasetID = dataset.DatasetID
+		return nil
+	})
+	if err != nil {
+		return "", fmt.Errorf("could not get dataset ID: %w", err)
+	}
+
+	return datasetID, nil
+}