github.com/dolthub/go-mysql-server@v0.18.0/sql/expression/function/aggregation/max_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 aggregation
    16  
    17  import (
    18  	"testing"
    19  	"time"
    20  
    21  	"github.com/stretchr/testify/require"
    22  
    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/types"
    26  )
    27  
    28  func TestMax_String(t *testing.T) {
    29  	assert := require.New(t)
    30  	m := NewMax(expression.NewGetField(0, types.Int32, "field", true))
    31  	assert.Equal("MAX(field)", m.String())
    32  }
    33  
    34  func TestMax_Eval_Int32(t *testing.T) {
    35  	assert := require.New(t)
    36  	ctx := sql.NewEmptyContext()
    37  
    38  	m := NewMax(expression.NewGetField(0, types.Int32, "field", true))
    39  	b, _ := m.NewBuffer()
    40  
    41  	b.Update(ctx, sql.NewRow(int32(7)))
    42  	b.Update(ctx, sql.NewRow(nil))
    43  	b.Update(ctx, sql.NewRow(int32(6)))
    44  
    45  	v, err := b.Eval(ctx)
    46  	assert.NoError(err)
    47  	assert.Equal(int32(7), v)
    48  }
    49  
    50  func TestMax_Eval_Text(t *testing.T) {
    51  	assert := require.New(t)
    52  	ctx := sql.NewEmptyContext()
    53  
    54  	m := NewMax(expression.NewGetField(0, types.Text, "field", true))
    55  	b, _ := m.NewBuffer()
    56  
    57  	b.Update(ctx, sql.NewRow("a"))
    58  	b.Update(ctx, sql.NewRow("A"))
    59  	b.Update(ctx, sql.NewRow("b"))
    60  
    61  	v, err := b.Eval(ctx)
    62  	assert.NoError(err)
    63  	assert.Equal("b", v)
    64  }
    65  
    66  func TestMax_Eval_Timestamp(t *testing.T) {
    67  	assert := require.New(t)
    68  	ctx := sql.NewEmptyContext()
    69  
    70  	m := NewMax(expression.NewGetField(0, types.Timestamp, "field", true))
    71  	b, _ := m.NewBuffer()
    72  
    73  	expected, _ := time.Parse(sql.TimestampDatetimeLayout, "2008-01-02 15:04:05")
    74  	someTime, _ := time.Parse(sql.TimestampDatetimeLayout, "2007-01-02 15:04:05")
    75  	otherTime, _ := time.Parse(sql.TimestampDatetimeLayout, "2006-01-02 15:04:05")
    76  
    77  	b.Update(ctx, sql.NewRow(someTime))
    78  	b.Update(ctx, sql.NewRow(expected))
    79  	b.Update(ctx, sql.NewRow(otherTime))
    80  
    81  	v, err := b.Eval(ctx)
    82  	assert.NoError(err)
    83  	assert.Equal(expected, v)
    84  }
    85  func TestMax_Eval_NULL(t *testing.T) {
    86  	assert := require.New(t)
    87  	ctx := sql.NewEmptyContext()
    88  
    89  	m := NewMax(expression.NewGetField(0, types.Int32, "field", true))
    90  	b, _ := m.NewBuffer()
    91  
    92  	b.Update(ctx, sql.NewRow(nil))
    93  	b.Update(ctx, sql.NewRow(nil))
    94  	b.Update(ctx, sql.NewRow(nil))
    95  
    96  	v, err := b.Eval(ctx)
    97  	assert.NoError(err)
    98  	assert.Equal(nil, v)
    99  }
   100  
   101  func TestMax_Eval_Empty(t *testing.T) {
   102  	assert := require.New(t)
   103  	ctx := sql.NewEmptyContext()
   104  
   105  	m := NewMax(expression.NewGetField(0, types.Int32, "field", true))
   106  	b, _ := m.NewBuffer()
   107  
   108  	v, err := b.Eval(ctx)
   109  	assert.NoError(err)
   110  	assert.Equal(nil, v)
   111  }
   112  
   113  func TestMax_Distinct(t *testing.T) {
   114  	assert := require.New(t)
   115  	ctx := sql.NewEmptyContext()
   116  
   117  	m := NewMax(expression.NewDistinctExpression(expression.NewGetField(0, types.Int32, "field", true)))
   118  	b, _ := m.NewBuffer()
   119  
   120  	require.Equal(t, "MAX(DISTINCT field)", m.String())
   121  
   122  	require.NoError(t, b.Update(ctx, sql.Row{1}))
   123  	require.NoError(t, b.Update(ctx, sql.Row{1}))
   124  	require.NoError(t, b.Update(ctx, sql.Row{2}))
   125  	require.NoError(t, b.Update(ctx, sql.Row{3}))
   126  	require.NoError(t, b.Update(ctx, sql.Row{3}))
   127  
   128  	v, err := b.Eval(ctx)
   129  	assert.NoError(err)
   130  	assert.Equal(3, v)
   131  
   132  	m = NewMax(expression.NewDistinctExpression(expression.NewGetField(0, types.Int32, "field", true)))
   133  	b, _ = m.NewBuffer()
   134  
   135  	require.NoError(t, b.Update(ctx, sql.Row{1}))
   136  	require.NoError(t, b.Update(ctx, sql.Row{nil}))
   137  	require.NoError(t, b.Update(ctx, sql.Row{1}))
   138  	require.NoError(t, b.Update(ctx, sql.Row{2}))
   139  	v, err = b.Eval(ctx)
   140  	assert.NoError(err)
   141  	assert.Equal(2, v)
   142  }