[PECO-1112] Added decimal handling (#167)

We need to dynamically set the actual values of decimals, and this
should be the smallest value that could hypothetically encompass the
decimal string.

parameter_test.go

@@ -19,7 +19,7 @@ func TestParameter_Inference(t *testing.T) {
  assert.Equal(t, string("TIMESTAMP"), *parameters[1].Type)
  assert.Equal(t, &cli_service.TSparkParameterValue{StringValue: strPtr("5")}, parameters[2].Value)
  assert.Equal(t, string("true"), *parameters[3].Value.StringValue)
- assert.Equal(t, string("DECIMAL"), *parameters[4].Type)
+ assert.Equal(t, string("DECIMAL(2,1)"), *parameters[4].Type)
  assert.Equal(t, string("6.2"), *parameters[4].Value.StringValue)
  })
 }
@@ -31,6 +31,6 @@ func TestParameters_Names(t *testing.T) {
  assert.Equal(t, cli_service.TSparkParameterValue{StringValue: strPtr("26")}, *parameters[0].Value)
  assert.Equal(t, string("2"), *parameters[1].Name)
  assert.Equal(t, cli_service.TSparkParameterValue{StringValue: strPtr("6.2")}, *parameters[1].Value)
- assert.Equal(t, string("DECIMAL"), *parameters[1].Type)
+ assert.Equal(t, string("DECIMAL(2,1)"), *parameters[1].Type)
  })
 }

parameters.go

@@ -4,6 +4,7 @@ import (
  "database/sql/driver"
  "fmt"
  "strconv"
+ "strings"
  "time"
 
  "github.com/databricks/databricks-sql-go/internal/cli_service"
@@ -142,9 +143,33 @@ func convertNamedValuesToSparkParams(values []driver.NamedValue) []*cli_service.
  for i := range sqlParams {
  sqlParam := sqlParams[i]
  sparkParamValue := sqlParam.Value.(string)
- sparkParamType := sqlParam.Type.String()
+ var sparkParamType string
+ if sqlParam.Type == Decimal {
+ sparkParamType = inferDecimalType(sparkParamValue)
+ } else {
+ sparkParamType = sqlParam.Type.String()
+ }
  sparkParam := cli_service.TSparkParameter{Name: &sqlParam.Name, Type: &sparkParamType, Value: &cli_service.TSparkParameterValue{StringValue: &sparkParamValue}}
  sparkParams = append(sparkParams, &sparkParam)
  }
  return sparkParams
 }
+
+func inferDecimalType(d string) (t string) {
+ var overall int
+ var after int
+ if strings.HasPrefix(d, "0.") {
+ // Less than one
+ overall = len(d) - 2
+ after = len(d) - 2
+ } else if !strings.Contains(d, ".") {
+ // Less than one
+ overall = len(d)
+ after = 0
+ } else {
+ components := strings.Split(d, ".")
+ overall, after = len(components[0])+len(components[1]), len(components[1])
+ }
+
+ return fmt.Sprintf("DECIMAL(%d,%d)", overall, after)
+}