Add NOT NULL constraint (#46)

* Add not null constraint (#42)

* Fix spacing between AttributeKey and Description

cmd/root.go

@@ -75,7 +75,7 @@ func init() {
 	rootCmd.Flags().StringP(config.SchemaKey, "s", "", "schema that should be used")
 	rootCmd.Flags().StringP(config.OutputFileNameKey, "o", "result.mmd", "output file name")
 	rootCmd.Flags().String(config.SchemaPrefixSeparator, ".", "the separator that should be used between schema and table name")
-	rootCmd.Flags().StringSlice(config.ShowDescriptionsKey, []string{""}, "show 'enumValues' and/or 'columnComments' in the description column")
+	rootCmd.Flags().StringSlice(config.ShowDescriptionsKey, []string{""}, "show 'notNull', 'enumValues' and/or 'columnComments' in the description column")
 	rootCmd.Flags().StringSlice(config.SelectedTablesKey, []string{""}, "tables to include")
 
 	bindFlagToViper(config.ShowAllConstraintsKey)

config/config_test.go

@@ -31,6 +31,7 @@ omitAttributeKeys: true
 showDescriptions:
   - enumValues
   - columnComments
+  - notNull
 useAllSchemas: true
 showSchemaPrefix: true
 schemaPrefixSeparator: "_"
@@ -58,7 +59,7 @@ connectionStringSuggestions:
 	assert.True(t, config.Debug())
 	assert.True(t, config.OmitConstraintLabels())
 	assert.True(t, config.OmitAttributeKeys())
-	assert.ElementsMatch(t, []string{"enumValues", "columnComments"}, config.ShowDescriptions())
+	assert.ElementsMatch(t, []string{"notNull", "enumValues", "columnComments"}, config.ShowDescriptions())
 	assert.True(t, config.UseAllSchemas())
 	assert.True(t, config.ShowSchemaPrefix())
 	assert.Equal(t, "_", config.SchemaPrefixSeparator())

database/database_integration_test.go

@@ -9,9 +9,10 @@ import (
 )
 
 type columnTestResult struct {
-	Name      string
-	isPrimary bool
-	isForeign bool
+	Name       string
+	isPrimary  bool
+	isForeign  bool
+	isNullable bool
 }
 
 type connectionParameter struct {
@@ -135,33 +136,34 @@ func TestDatabaseIntegrations(t *testing.T) {
 					expectedColumns []columnTestResult
 				}{
 					{tableName: "article", expectedColumns: []columnTestResult{
-						{Name: "id", isPrimary: true, isForeign: false},
-						{Name: "title", isPrimary: false, isForeign: false},
+						{Name: "id", isPrimary: true, isForeign: false, isNullable: false},
+						{Name: "title", isPrimary: false, isForeign: false, isNullable: false},
+						{Name: "subtitle", isPrimary: false, isForeign: false, isNullable: true},
 					}},
 					{tableName: "article_detail", expectedColumns: []columnTestResult{
-						{Name: "id", isPrimary: true, isForeign: true},
-						{Name: "created_at", isPrimary: false, isForeign: false},
+						{Name: "id", isPrimary: true, isForeign: true, isNullable: false},
+						{Name: "created_at", isPrimary: false, isForeign: false, isNullable: false},
 					}},
 					{tableName: "article_comment", expectedColumns: []columnTestResult{
-						{Name: "id", isPrimary: true, isForeign: false},
-						{Name: "article_id", isPrimary: false, isForeign: true},
-						{Name: "comment", isPrimary: false, isForeign: false},
+						{Name: "id", isPrimary: true, isForeign: false, isNullable: false},
+						{Name: "article_id", isPrimary: false, isForeign: true, isNullable: false},
+						{Name: "comment", isPrimary: false, isForeign: false, isNullable: false},
 					}},
 					{tableName: "label", expectedColumns: []columnTestResult{
-						{Name: "id", isPrimary: true, isForeign: false},
-						{Name: "label", isPrimary: false, isForeign: false},
+						{Name: "id", isPrimary: true, isForeign: false, isNullable: false},
+						{Name: "label", isPrimary: false, isForeign: false, isNullable: false},
 					}},
 					{tableName: "article_label", expectedColumns: []columnTestResult{
-						{Name: "article_id", isPrimary: true, isForeign: true},
-						{Name: "label_id", isPrimary: true, isForeign: true},
+						{Name: "article_id", isPrimary: true, isForeign: true, isNullable: false},
+						{Name: "label_id", isPrimary: true, isForeign: true, isNullable: false},
 					}},
 					{tableName: "test_1_a", expectedColumns: []columnTestResult{
-						{Name: "id", isPrimary: true, isForeign: false},
-						{Name: "xid", isPrimary: true, isForeign: false},
+						{Name: "id", isPrimary: true, isForeign: false, isNullable: false},
+						{Name: "xid", isPrimary: true, isForeign: false, isNullable: false},
 					}},
 					{tableName: "test_1_b", expectedColumns: []columnTestResult{
-						{Name: "aid", isPrimary: true, isForeign: true},
-						{Name: "bid", isPrimary: true, isForeign: true},
+						{Name: "aid", isPrimary: true, isForeign: true, isNullable: false},
+						{Name: "bid", isPrimary: true, isForeign: true, isNullable: false},
 					}},
 				}
 
@@ -177,9 +179,10 @@ func TestDatabaseIntegrations(t *testing.T) {
 						// Assert
 						for _, column := range columns {
 							columnResult = append(columnResult, columnTestResult{
-								Name:      column.Name,
-								isPrimary: column.IsPrimary,
-								isForeign: column.IsForeign,
+								Name:       column.Name,
+								isPrimary:  column.IsPrimary,
+								isForeign:  column.IsForeign,
+								isNullable: column.IsNullable,
 							})
 						}
 

database/mssql.go

@@ -102,6 +102,7 @@ func (c *mssqlConnector) GetColumns(tableName TableDetail) ([]ColumnResult, erro
 				where cu.column_name = c.column_name
 				  and cu.table_name = c.table_name
 				  and tc.constraint_type = 'FOREIGN KEY') as is_foreign,
+		    	case when c.is_nullable = 'YES' then 1 else 0 end as is_nullable,
 			   (select ISNULL(ep.value, '') from sys.tables t
 			      inner join sys.columns col on col.object_id = t.object_id and col.name = c.column_name
 				  left join sys.extended_properties ep on ep.major_id = t.object_id and ep.minor_id = col.column_id
@@ -117,7 +118,7 @@ func (c *mssqlConnector) GetColumns(tableName TableDetail) ([]ColumnResult, erro
 	var columns []ColumnResult
 	for rows.Next() {
 		var column ColumnResult
-		if err = rows.Scan(&column.Name, &column.DataType, &column.IsPrimary, &column.IsForeign, &column.Comment); err != nil {
+		if err = rows.Scan(&column.Name, &column.DataType, &column.IsPrimary, &column.IsForeign, &column.IsNullable, &column.Comment); err != nil {
 			return nil, err
 		}
 

database/mysql.go

@@ -99,6 +99,7 @@ func (c *mySqlConnector) GetColumns(tableName TableDetail) ([]ColumnResult, erro
 				where cu.column_name = c.column_name
 				  and cu.table_name = c.table_name
 				  and tc.constraint_type = 'FOREIGN KEY') as is_foreign,
+		    	IF(c.is_nullable = 'YES', 1, 0) as is_nullable,
         case when c.data_type = 'enum' then REPLACE(REPLACE(REPLACE(REPLACE(c.column_type, 'enum', ''), '\'', ''), '(', ''), ')', '') else '' end as enum_values,
 		c.column_comment as comment
 		from information_schema.columns c
@@ -112,7 +113,7 @@ func (c *mySqlConnector) GetColumns(tableName TableDetail) ([]ColumnResult, erro
 	var columns []ColumnResult
 	for rows.Next() {
 		var column ColumnResult
-		if err = rows.Scan(&column.Name, &column.DataType, &column.IsPrimary, &column.IsForeign, &column.EnumValues, &column.Comment); err != nil {
+		if err = rows.Scan(&column.Name, &column.DataType, &column.IsPrimary, &column.IsForeign, &column.IsNullable, &column.EnumValues, &column.Comment); err != nil {
 			return nil, err
 		}
 

database/postgres.go

@@ -101,6 +101,7 @@ func (c *postgresConnector) GetColumns(tableName TableDetail) ([]ColumnResult, e
                 where cu.column_name = c.column_name
                   and cu.table_name = c.table_name
                   and tc.constraint_type = 'FOREIGN KEY')                      as is_foreign,
+               bool_or(c.is_nullable = 'YES')                                  as is_not_null,
                coalesce(string_agg(enumlabel, ',' order by enumsortorder), '') as enum_values,
                coalesce(pd.description, '')                   				   as comment
         from information_schema.columns c
@@ -125,7 +126,7 @@ func (c *postgresConnector) GetColumns(tableName TableDetail) ([]ColumnResult, e
 	var columns []ColumnResult
 	for rows.Next() {
 		var column ColumnResult
-		if err = rows.Scan(&column.Name, &column.DataType, &column.IsPrimary, &column.IsForeign, &column.EnumValues, &column.Comment); err != nil {
+		if err = rows.Scan(&column.Name, &column.DataType, &column.IsPrimary, &column.IsForeign, &column.IsNullable, &column.EnumValues, &column.Comment); err != nil {
 			return nil, err
 		}
 

database/result.go

@@ -20,6 +20,7 @@ type ColumnResult struct {
 	DataType   string
 	IsPrimary  bool
 	IsForeign  bool
+	IsNullable bool
 	EnumValues string
 	Comment    string
 }

diagram/diagram_util.go

@@ -57,6 +57,10 @@ func getDescription(options []string, column database.ColumnResult) string {
 	var description []string
 	for _, option := range options {
 		switch option {
+		case "notNull":
+			if !column.IsNullable {
+				description = append(description, "{NOT_NULL}")
+			}
 		case "enumValues":
 			if column.EnumValues != "" {
 				description = append(description, "<"+column.EnumValues+">")

diagram/erd_template.gommd

@@ -3,7 +3,7 @@ erDiagram
 {{- range .Tables}}
     {{.Name}} {
     {{- range .Columns}}
-        {{.DataType}} {{.Name}} {{.AttributeKey}} {{- if .Description}}"{{.Description}}"{{end -}}
+        {{.DataType}} {{.Name}} {{- if .AttributeKey}} {{.AttributeKey}}{{end -}} {{- if .Description}} "{{.Description}}"{{end -}}
     {{- end}}
     }
 {{end -}}

exampleRunConfig.yaml

@@ -23,5 +23,6 @@ omitAttributeKeys: false
 showDescriptions:
   - enumValues
   - columnComments
+  - notNull
 showSchemaPrefix: true
 schemaPrefixSeparator: "_"

readme.md

@@ -45,6 +45,7 @@ for your operating system. To be able to use it globally on your system, add the
 * Show primary and foreign keys
 * Show enum values of enum column
 * Show column comments
+* Show NOT NULL constraints
 
 ## Why would I need it / Why should I care?
 
@@ -81,7 +82,7 @@ via `mermerd -h`
       --schemaPrefixSeparator string  the separator that should be used between schema and table name (default ".")
       --selectedTables strings        tables to include
       --showAllConstraints            show all constraints, even though the table of the resulting constraint was not selected
-      --showDescriptions strings      show 'enumValues' and/or 'columnComments' in the description column
+      --showDescriptions strings      show 'notNull', enumValues' and/or 'columnComments' in the description column
       --showSchemaPrefix              show schema prefix in table name
       --useAllSchemas                 use all available schemas
       --useAllTables                  use all available tables
@@ -148,6 +149,7 @@ omitAttributeKeys: true
 showDescriptions:
   - enumValues
   - columnComments
+  - notNull
 showSchemaPrefix: true
 schemaPrefixSeparator: "_"
 ```
@@ -173,8 +175,8 @@ mermerd -c "postgresql://user:password@localhost:5432/yourDb" -s public --useAll
 # same as previous one, but use a list of tables without interaction
 mermerd -c "postgresql://user:password@localhost:5432/yourDb" -s public --selectedTables article,article_label
 
-# show enum values and column comments in the description column
-mermerd -c "postgresql://user:password@localhost:5432/yourDb" -s public --useAllTables --showDescriptions enumValues,columnComments
+# show enum values, column comments and notNull in the description column
+mermerd -c "postgresql://user:password@localhost:5432/yourDb" -s public --useAllTables --showDescriptions enumValues,columnComments,notNull
 ```
 
 ## Connection strings

test/db-table-setup.sql

@@ -1,7 +1,8 @@
 create table article
 (
     id    int          not null primary key,
-    title varchar(255) not null
+    title varchar(255) not null,
+    subtitle varchar(255)
 );
 
 create table article_detail