fix float type parameter in stmt

context.go

@@ -70,20 +70,3 @@ func getCatalog(ctx context.Context) (string, bool) {
 	val, ok := ctx.Value(CatalogContextKey).(string)
 	return val, ok
 }
-
-/*
- * force using string type with numeric string
- */
-const forceNumericContextKey string = "force_numeric_string_key"
-
-// ForceNumericStringContextKey context key of force numeric string
-var ForceNumericStringContextKey = contextPrefix + forceNumericContextKey
-
-func SetForceNumericString(ctx context.Context, val bool) context.Context {
-	return context.WithValue(ctx, ForceNumericStringContextKey, val)
-}
-
-func getForNumericString(ctx context.Context) bool {
-	val, ok := ctx.Value(ForceNumericStringContextKey).(bool)
-	return val && ok
-}

context_test.go

@@ -5,37 +5,6 @@ import (
 	"testing"
 )
 
-func Test_getForNumericString(t *testing.T) {
-	tests := []struct {
-		name string
-		ctx  context.Context
-		want bool
-	}{
-		{
-			name: "Default",
-			ctx:  context.Background(),
-			want: false,
-		},
-		{
-			name: "SetForceNumericString:true",
-			ctx:  SetForceNumericString(context.Background(), true),
-			want: true,
-		},
-		{
-			name: "SetForceNumericString:false",
-			ctx:  SetForceNumericString(context.Background(), false),
-			want: false,
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			if got := getForNumericString(tt.ctx); got != tt.want {
-				t.Errorf("getForNumericString() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
 func Test_getCatalog(t *testing.T) {
 	tests := []struct {
 		name  string

db_test.go

@@ -7,7 +7,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"os"
-	"strconv"
 	"strings"
 	"testing"
 	"time"
@@ -229,17 +228,15 @@ func TestPrepare(t *testing.T) {
 		},
 		{
 			name:   "FloatType",
-			sql:    fmt.Sprintf("select * from %s where cast(floattype as decimal(8,7)) = ?", harness.table),
-			params: []interface{}{strconv.FormatFloat(float64(data[0].FloatType), 'f', -1, 32)},
+			sql:    fmt.Sprintf("select * from %s where floattype = ?", harness.table),
+			params: []interface{}{data[0].FloatType},
 			want:   data[0],
 		},
 		{
-			name:      "Numeric String",
-			sql:       fmt.Sprintf("select * from %s where stringType = ?", harness.table),
-			params:    []interface{}{data[2].StringType},
-			startFunc: func(ctx context.Context) context.Context { return SetForceNumericString(ctx, true) },
-			endFunc:   func(ctx context.Context) context.Context { return SetForceNumericString(ctx, false) },
-			want:      data[2],
+			name:   "DoubleType",
+			sql:    fmt.Sprintf("select * from %s where doubletype = ?", harness.table),
+			params: []interface{}{data[0].DoubleType},
+			want:   data[0],
 		},
 	}
 

doc/prepared_statements.md

@@ -44,60 +44,10 @@ You can use [Prepared Statements on Athena](https://docs.aws.amazon.com/athena/l
 
 ## Examples
 
-#### int parameter
-
 ```
 intParam := 1
-stmt, _ := db.PrepareContext(ctx, "SELECT * FROM test_table WHERE int_column = ?")
-rows, _ := stmt.QueryContext(ctx, intParam) 
-```
-execute `SELECT * FROM test_table WHERE int_column = 1`
-
-#### string parameter
-
-```
 stringParam := "string value"
-stmt, _ := db.PrepareContext(ctx, "SELECT * FROM test_table WHERE string_column = ?")
-rows, _ := stmt.QueryContext(ctx, stringParam) 
-```
-execute `SELECT * FROM test_table WHERE string_column = 'string value'`
-
-#### float parameter
-
-Neither float32 nor float64 is supported because digit precision will easily cause large problems.
-If you want to set a parameter for float type column on Athena, please use string type parameter whose characters are all numeric.
-
+stmt, _ := db.PrepareContext(ctx, "SELECT * FROM test_table WHERE int_column = ? AND string_column = ?")
+rows, _ := stmt.QueryContext(ctx, intParam, stringParam)
 ```
-// for float column
-floatParam := "3.144"
-stmt, _ := db.PrepareContext(ctx, "SELECT * FROM test_table WHERE float_column = ?")
-rows, _ := stmt.QueryContext(ctx, floatParam) 
-```
-execute SQL `SELECT * FROM test_table WHERE float_column = 3.144`
-
-|golang (string)|in SQL|
-| --- | --- |
-|"123"|123|
-|"1.23"|1.23|
-|"1.23a"|'1.23a'|
-
-#### for numeric string parameter 
-
-By default, numeric string parameter isn't converted to string type in SQL, as shown in the float parameter example.
-If you want to set a numeric value for a string type column on Athena, put true in SetForceNumericString function.
-
-```
-// for string column
-floatParam := "3.144"
-stmt, _ := db.PrepareContext(ctx, "SELECT * FROM test_table WHERE string_column = ?")
-ctx = SetForceNumericString(ctx, true) // set true
-rows, _ := stmt.QueryContext(ctx, floatParam) 
-```
-execute SQL `SELECT * FROM test_table WHERE string_column = '3.144'`
-
-**under setting true in SetForceNumericString**
-
-|golang (string)|in SQL|
-| --- | --- |
-|"123"|'123'|
-|"1.23"|'1.23'|
+execute `SELECT * FROM test_table WHERE int_column = 1 and string_column = 'string value'`

stmt.go

@@ -154,13 +154,11 @@ func (s *stmtAthena) runQuery(ctx context.Context, query string) (driver.Rows, e
 }
 
 func serial(ctx context.Context, v interface{}) (string, error) {
-	forceNumericString := getForNumericString(ctx)
-	if !forceNumericString {
-		if x, ok := v.(string); ok {
-			if _, err := strconv.ParseFloat(string(x), 64); err == nil {
-				return presto.Serial(presto.Numeric(x))
-			}
-		}
+	switch x := v.(type) {
+	case float32:
+		return strconv.FormatFloat(float64(x), 'g', -1, 32), nil
+	case float64:
+		return strconv.FormatFloat(x, 'g', -1, 64), nil
 	}
 
 	return presto.Serial(v)