Add Column Metadata

README.md

@@ -217,6 +217,7 @@ It only asserts that argument is of `time.Time` type.
 
 ## Change Log
 
+- **2019-04-06** - added functionality to mock a sql MetaData request
 - **2019-02-13** - added `go.mod` removed the references and suggestions using `gopkg.in`.
 - **2018-12-11** - added expectation of Rows to be closed, while mocking expected query.
 - **2018-12-11** - introduced an option to provide **QueryMatcher** in order to customize SQL query matching.

column.go

@@ -0,0 +1,77 @@
+package sqlmock
+
+import "reflect"
+
+// Column is a mocked column Metadata for rows.ColumnTypes()
+type Column struct {
+	name       string
+	dbType     string
+	nullable   bool
+	nullableOk bool
+	length     int64
+	lengthOk   bool
+	precision  int64
+	scale      int64
+	psOk       bool
+	scanType   reflect.Type
+}
+
+func (c *Column) Name() string {
+	return c.name
+}
+
+func (c *Column) DbType() string {
+	return c.dbType
+}
+
+func (c *Column) IsNullable() (bool, bool) {
+	return c.nullable, c.nullableOk
+}
+
+func (c *Column) Length() (int64, bool) {
+	return c.length, c.lengthOk
+}
+
+func (c *Column) PrecisionScale() (int64, int64, bool) {
+	return c.precision, c.scale, c.psOk
+}
+
+func (c *Column) ScanType() reflect.Type {
+	return c.scanType
+}
+
+// NewColumn returns a Column with specified name
+func NewColumn(name string) *Column {
+	return &Column{
+		name: name,
+	}
+}
+
+// Nullable returns the column with nullable metadata set
+func (c *Column) Nullable(nullable bool) *Column {
+	c.nullable = nullable
+	c.nullableOk = true
+	return c
+}
+
+// OfType returns the column with type metadata set
+func (c *Column) OfType(dbType string, sampleValue interface{}) *Column {
+	c.dbType = dbType
+	c.scanType = reflect.TypeOf(sampleValue)
+	return c
+}
+
+// WithLength returns the column with length metadata set.
+func (c *Column) WithLength(length int64) *Column {
+	c.length = length
+	c.lengthOk = true
+	return c
+}
+
+// WithPrecisionAndScale returns the column with precision and scale metadata set.
+func (c *Column) WithPrecisionAndScale(precision, scale int64) *Column {
+	c.precision = precision
+	c.scale = scale
+	c.psOk = true
+	return c
+}

column_test.go

@@ -0,0 +1,63 @@
+package sqlmock
+
+import (
+	"reflect"
+	"testing"
+	"time"
+)
+
+func TestColumn(t *testing.T) {
+	now, _ := time.Parse(time.RFC3339, "2020-06-20T22:08:41Z")
+	column1 := NewColumn("test").OfType("VARCHAR", "").Nullable(true).WithLength(100)
+	column2 := NewColumn("number").OfType("DECIMAL", float64(0.0)).Nullable(false).WithPrecisionAndScale(10, 4)
+	column3 := NewColumn("when").OfType("TIMESTAMP", now)
+
+	if column1.ScanType().Kind() != reflect.String {
+		t.Errorf("string scanType mismatch: %v", column1.ScanType())
+	}
+	if column2.ScanType().Kind() != reflect.Float64 {
+		t.Errorf("float scanType mismatch: %v", column2.ScanType())
+	}
+	if column3.ScanType() != reflect.TypeOf(time.Time{}) {
+		t.Errorf("time scanType mismatch: %v", column3.ScanType())
+	}
+
+	nullable, ok := column1.IsNullable()
+	if !nullable || !ok {
+		t.Errorf("'test' column should be nullable")
+	}
+	nullable, ok = column2.IsNullable()
+	if nullable || !ok {
+		t.Errorf("'number' column should not be nullable")
+	}
+	nullable, ok = column3.IsNullable()
+	if ok {
+		t.Errorf("'when' column nullability should be unknown")
+	}
+
+	length, ok := column1.Length()
+	if length != 100 || !ok {
+		t.Errorf("'test' column wrong length")
+	}
+	length, ok = column2.Length()
+	if ok {
+		t.Errorf("'number' column is not of variable length type")
+	}
+	length, ok = column3.Length()
+	if ok {
+		t.Errorf("'when' column is not of variable length type")
+	}
+
+	_, _, ok = column1.PrecisionScale()
+	if ok {
+		t.Errorf("'test' column not applicable")
+	}
+	precision, scale, ok := column2.PrecisionScale()
+	if precision != 10 || scale != 4 || !ok {
+		t.Errorf("'number' column not applicable")
+	}
+	_, _, ok = column3.PrecisionScale()
+	if ok {
+		t.Errorf("'when' column not applicable")
+	}
+}

expectations_go18.go

@@ -12,11 +12,19 @@ import (
 // WillReturnRows specifies the set of resulting rows that will be returned
 // by the triggered query
 func (e *ExpectedQuery) WillReturnRows(rows ...*Rows) *ExpectedQuery {
+	defs := 0
 	sets := make([]*Rows, len(rows))
 	for i, r := range rows {
 		sets[i] = r
+		if r.def != nil {
+			defs++
+		}
+	}
+	if defs > 0 && defs == len(sets) {
+		e.rows = &rowSetsWithDefinition{&rowSets{sets: sets, ex: e}}
+	} else {
+		e.rows = &rowSets{sets: sets, ex: e}
 	}
-	e.rows = &rowSets{sets: sets, ex: e}
 	return e
 }
 

rows.go

@@ -120,6 +120,7 @@ func (rs *rowSets) invalidateRaw() {
 type Rows struct {
 	converter driver.ValueConverter
 	cols      []string
+	def       []*Column
 	rows      [][]driver.Value
 	pos       int
 	nextErr   map[int]error

rows_go18.go

@@ -2,7 +2,11 @@
 
 package sqlmock
 
-import "io"
+import (
+	"database/sql/driver"
+	"io"
+	"reflect"
+)
 
 // Implement the "RowsNextResultSet" interface
 func (rs *rowSets) HasNextResultSet() bool {
@@ -18,3 +22,53 @@ func (rs *rowSets) NextResultSet() error {
 	rs.pos++
 	return nil
 }
+
+// type for rows with columns definition created with sqlmock.NewRowsWithColumnDefinition
+type rowSetsWithDefinition struct {
+	*rowSets
+}
+
+// Implement the "RowsColumnTypeDatabaseTypeName" interface
+func (rs *rowSetsWithDefinition) ColumnTypeDatabaseTypeName(index int) string {
+	return rs.getDefinition(index).DbType()
+}
+
+// Implement the "RowsColumnTypeLength" interface
+func (rs *rowSetsWithDefinition) ColumnTypeLength(index int) (length int64, ok bool) {
+	return rs.getDefinition(index).Length()
+}
+
+// Implement the "RowsColumnTypeNullable" interface
+func (rs *rowSetsWithDefinition) ColumnTypeNullable(index int) (nullable, ok bool) {
+	return rs.getDefinition(index).IsNullable()
+}
+
+// Implement the "RowsColumnTypePrecisionScale" interface
+func (rs *rowSetsWithDefinition) ColumnTypePrecisionScale(index int) (precision, scale int64, ok bool) {
+	return rs.getDefinition(index).PrecisionScale()
+}
+
+// ColumnTypeScanType is defined from driver.RowsColumnTypeScanType
+func (rs *rowSetsWithDefinition) ColumnTypeScanType(index int) reflect.Type {
+	return rs.getDefinition(index).ScanType()
+}
+
+// return column definition from current set metadata
+func (rs *rowSetsWithDefinition) getDefinition(index int) *Column {
+	return rs.sets[rs.pos].def[index]
+}
+
+// NewRowsWithColumnDefinition return rows with columns metadata
+func NewRowsWithColumnDefinition(columns ...*Column) *Rows {
+	cols := make([]string, len(columns))
+	for i, column := range columns {
+		cols[i] = column.Name()
+	}
+
+	return &Rows{
+		cols:      cols,
+		def:       columns,
+		nextErr:   make(map[int]error),
+		converter: driver.DefaultParameterConverter,
+	}
+}