github.com/dolthub/dolt/go@v0.40.5-0.20240520175717-68db7794bea6/libraries/doltcore/sqle/show_create_table.go (about)

     1  // Copyright 2020 Dolthub, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package sqle
    16  
    17  import (
    18  	"context"
    19  	"fmt"
    20  
    21  	sqle "github.com/dolthub/go-mysql-server"
    22  	"github.com/dolthub/go-mysql-server/sql"
    23  
    24  	"github.com/dolthub/dolt/go/libraries/doltcore/env"
    25  	"github.com/dolthub/dolt/go/libraries/doltcore/sqle/dsess"
    26  )
    27  
    28  // These functions cannot be in the sqlfmt package as the reliance on the sqle package creates a circular reference.
    29  
    30  func PrepareCreateTableStmt(ctx context.Context, sqlDb dsess.SqlDatabase) (*sql.Context, *sqle.Engine, *dsess.DoltSession) {
    31  	pro, err := NewDoltDatabaseProviderWithDatabase(env.DefaultInitBranch, nil, sqlDb, nil)
    32  	if err != nil {
    33  		return nil, nil, nil
    34  	}
    35  	engine := sqle.NewDefault(pro)
    36  
    37  	sess := dsess.DefaultSession(pro)
    38  	sqlCtx := sql.NewContext(ctx, sql.WithSession(sess))
    39  	sqlCtx.SetCurrentDatabase(sqlDb.Name())
    40  	return sqlCtx, engine, sess
    41  }
    42  
    43  func GetCreateTableStmt(ctx *sql.Context, engine *sqle.Engine, tableName string) (string, error) {
    44  	_, rowIter, err := engine.Query(ctx, fmt.Sprintf("SHOW CREATE TABLE `%s`;", tableName))
    45  	if err != nil {
    46  		return "", err
    47  	}
    48  	rows, err := sql.RowIterToRows(ctx, rowIter)
    49  	if err != nil {
    50  		return "", err
    51  	}
    52  	if len(rows) != 1 || len(rows[0]) != 2 {
    53  		return "", fmt.Errorf("unexpected result from SHOW CREATE TABLE")
    54  	}
    55  	stmt, ok := rows[0][1].(string)
    56  	if !ok {
    57  		return "", fmt.Errorf("expected string statement from SHOW CREATE TABLE")
    58  	}
    59  	return stmt + ";", nil
    60  }