github.com/dolthub/go-mysql-server@v0.18.0/sql/rowexec/subquery_test.go (about)

     1  // Copyright 2020-2021 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 rowexec
    16  
    17  import (
    18  	"testing"
    19  
    20  	"github.com/stretchr/testify/require"
    21  
    22  	"github.com/dolthub/go-mysql-server/memory"
    23  	"github.com/dolthub/go-mysql-server/sql"
    24  	"github.com/dolthub/go-mysql-server/sql/expression"
    25  	"github.com/dolthub/go-mysql-server/sql/plan"
    26  	"github.com/dolthub/go-mysql-server/sql/types"
    27  )
    28  
    29  func TestSubquery(t *testing.T) {
    30  	require := require.New(t)
    31  	db := memory.NewDatabase("test")
    32  	pro := memory.NewDBProvider(db)
    33  	ctx := newContext(pro)
    34  
    35  	table := memory.NewTable(db, "", sql.PrimaryKeySchema{}, nil)
    36  	require.NoError(table.Insert(ctx, nil))
    37  
    38  	subquery := plan.NewSubquery(plan.NewProject(
    39  		[]sql.Expression{
    40  			expression.NewLiteral("one", types.LongText),
    41  		},
    42  		plan.NewResolvedTable(table, nil, nil),
    43  	), "select 'one'").WithExecBuilder(DefaultBuilder)
    44  
    45  	value, err := subquery.Eval(ctx, nil)
    46  	require.NoError(err)
    47  	require.Equal(value, "one")
    48  }
    49  
    50  func TestSubqueryTooManyRows(t *testing.T) {
    51  	require := require.New(t)
    52  	db := memory.NewDatabase("test")
    53  	pro := memory.NewDBProvider(db)
    54  	ctx := newContext(pro)
    55  
    56  	table := memory.NewTable(db, "", sql.PrimaryKeySchema{}, nil)
    57  	require.NoError(table.Insert(ctx, nil))
    58  	require.NoError(table.Insert(ctx, nil))
    59  
    60  	subquery := plan.NewSubquery(plan.NewProject(
    61  		[]sql.Expression{
    62  			expression.NewLiteral("one", types.LongText),
    63  		},
    64  		plan.NewResolvedTable(table, nil, nil),
    65  	), "select 'one'").WithExecBuilder(DefaultBuilder)
    66  
    67  	_, err := subquery.Eval(ctx, nil)
    68  	require.Error(err)
    69  }
    70  
    71  func TestSubqueryMultipleRows(t *testing.T) {
    72  	require := require.New(t)
    73  
    74  	db := memory.NewDatabase("test")
    75  	pro := memory.NewDBProvider(db)
    76  	ctx := newContext(pro)
    77  
    78  	table := memory.NewTable(db, "foo", sql.NewPrimaryKeySchema(sql.Schema{
    79  		{Name: "t", Source: "foo", Type: types.Text},
    80  	}), nil)
    81  
    82  	require.NoError(table.Insert(ctx, sql.Row{"one"}))
    83  	require.NoError(table.Insert(ctx, sql.Row{"two"}))
    84  	require.NoError(table.Insert(ctx, sql.Row{"three"}))
    85  
    86  	subquery := plan.NewSubquery(plan.NewProject(
    87  		[]sql.Expression{
    88  			expression.NewGetField(0, types.Text, "t", false),
    89  		},
    90  		plan.NewResolvedTable(table, nil, nil),
    91  	), "select t from foo").WithExecBuilder(DefaultBuilder)
    92  
    93  	values, err := subquery.EvalMultiple(ctx, nil)
    94  	require.NoError(err)
    95  	require.Equal(values, []interface{}{"one", "two", "three"})
    96  }