Add option to use stdout

analyzer/analyzer.go

@@ -123,7 +123,7 @@ func (a analyzer) GetTables(db database.Connector, selectedSchemas []string) ([]
 		return util.Map2(selectedTables, func(value string) database.TableDetail {
 			res, err := database.ParseTableName(value, selectedSchemas)
 			if err != nil {
-				logrus.Error("Could not parse table name", value)
+				logrus.Error("Could not parse table name ", value)
 			}
 
 			return res
@@ -165,7 +165,7 @@ func (a analyzer) GetTables(db database.Connector, selectedSchemas []string) ([]
 	return util.Map2(surveyResult, func(value string) database.TableDetail {
 		res, err := database.ParseTableName(value, selectedSchemas)
 		if err != nil {
-			logrus.Error("Could not parse table name", value)
+			logrus.Error("Could not parse table name ", value)
 		}
 
 		return res

changelog.md

@@ -4,15 +4,20 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), and this project adheres
 to [Semantic Versioning](https://semver.org/spec/v2.0.0.html) (after version 0.0.5).
 
+## [0.12.0] - 2024-0
+### Added
+- new `--outputMode` option ([PR #63](https://github.com/KarnerTh/mermerd/pull/63))
+
+### Changed
+- go 1.23 is now used
+
 ## [0.11.0] - 2024-06-16
 ### Added
 - new `--ignoreTables` option ([PR #59](https://github.com/KarnerTh/mermerd/pull/59))
 
 ### Changed
 - go 1.22 is now used
 
-### Fixed
-
 ## [0.10.0] - 2023-11-21
 ### Added
 - Support relationship labels ([PR #50](https://github.com/KarnerTh/mermerd/pull/50))
@@ -155,6 +160,8 @@ by `--showDescriptions enumValues` (for details see [PR #32](https://github.com/
 ### Added
 - Initial release of mermerd
 
+[0.12.0]: https://github.com/KarnerTh/mermerd/releases/tag/v0.12.0
+
 [0.11.0]: https://github.com/KarnerTh/mermerd/releases/tag/v0.11.0
 
 [0.10.0]: https://github.com/KarnerTh/mermerd/releases/tag/v0.10.0

cmd/root.go

@@ -5,7 +5,6 @@ import (
 	"io"
 	"os"
 
-	"github.com/fatih/color"
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
@@ -24,14 +23,18 @@ var rootCmd = &cobra.Command{
 	Short: "Create Mermaid ERD diagrams from existing tables",
 	Long:  "Create Mermaid ERD diagrams from existing tables",
 	Run: func(cmd *cobra.Command, args []string) {
-		presentation.ShowIntro()
-		config := config.NewConfig()
+		conf := config.NewConfig()
+		if runConfig != "" {
+			presentation.ShowInfo(conf, fmt.Sprintf("Using run configuration (from %s)", runConfig))
+		}
+
+		presentation.ShowIntro(conf)
 		connectorFactory := database.NewConnectorFactory()
 		questioner := analyzer.NewQuestioner()
-		analyzer := analyzer.NewAnalyzer(config, connectorFactory, questioner)
-		diagram := diagram.NewDiagram(config)
+		analyzer := analyzer.NewAnalyzer(conf, connectorFactory, questioner)
+		diagram := diagram.NewDiagram(conf)
 
-		if !config.Debug() {
+		if !conf.Debug() {
 			logrus.SetOutput(io.Discard)
 		}
 
@@ -42,14 +45,33 @@ var rootCmd = &cobra.Command{
 			os.Exit(1)
 		}
 
-		err = diagram.Create(result)
+		var wr io.Writer
+		if conf.OutputMode() == config.File {
+			f, err := os.Create(conf.OutputFileName())
+			defer f.Close()
+			if err != nil {
+				logrus.Error(err)
+				presentation.ShowError()
+				os.Exit(1)
+			}
+
+			wr = f
+		} else if conf.OutputMode() == config.Stdout {
+			wr = os.Stdout
+		} else {
+			logrus.Errorf("Output mode %s not suppported", conf.OutputMode())
+			presentation.ShowError()
+			os.Exit(1)
+		}
+
+		err = diagram.Create(wr, result)
 		if err != nil {
 			logrus.Error(err)
 			presentation.ShowError()
 			os.Exit(1)
 		}
 
-		presentation.ShowSuccess(config.OutputFileName())
+		presentation.ShowSuccess(conf, conf.OutputFileName())
 	},
 }
 
@@ -76,24 +98,27 @@ 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")
+	var outputMode = config.File
+	rootCmd.Flags().Var(&outputMode, config.OutputMode, `output mode (file, stdout)`)
 	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)
-	bindFlagToViper(config.UseAllTablesKey)
-	bindFlagToViper(config.IgnoreTables)
-	bindFlagToViper(config.UseAllSchemasKey)
+	bindFlagToViper(config.ConnectionStringKey)
 	bindFlagToViper(config.DebugKey)
-	bindFlagToViper(config.OmitConstraintLabelsKey)
-	bindFlagToViper(config.OmitAttributeKeysKey)
 	bindFlagToViper(config.EncloseWithMermaidBackticksKey)
-	bindFlagToViper(config.ConnectionStringKey)
-	bindFlagToViper(config.SchemaKey)
+	bindFlagToViper(config.IgnoreTables)
+	bindFlagToViper(config.OmitAttributeKeysKey)
+	bindFlagToViper(config.OmitConstraintLabelsKey)
 	bindFlagToViper(config.OutputFileNameKey)
+	bindFlagToViper(config.OutputMode)
+	bindFlagToViper(config.SchemaKey)
+	bindFlagToViper(config.SchemaPrefixSeparator)
 	bindFlagToViper(config.SelectedTablesKey)
+	bindFlagToViper(config.ShowAllConstraintsKey)
 	bindFlagToViper(config.ShowDescriptionsKey)
 	bindFlagToViper(config.ShowSchemaPrefix)
-	bindFlagToViper(config.SchemaPrefixSeparator)
+	bindFlagToViper(config.UseAllSchemasKey)
+	bindFlagToViper(config.UseAllTablesKey)
 }
 
 func bindFlagToViper(key string) {
@@ -102,7 +127,6 @@ func bindFlagToViper(key string) {
 
 func initConfig() {
 	if runConfig != "" {
-		color.Blue(fmt.Sprintf("Using run configuration (from %s)", runConfig))
 		viper.SetConfigFile(runConfig)
 	} else {
 		home, err := os.UserHomeDir()

config/config.go

@@ -3,45 +3,47 @@ package config
 import "github.com/spf13/viper"
 
 const (
-	ShowAllConstraintsKey          = "showAllConstraints"
-	UseAllTablesKey                = "useAllTables"
-	IgnoreTables                   = "ignoreTables"
-	SelectedTablesKey              = "selectedTables"
-	SchemaKey                      = "schema"
 	ConnectionStringKey            = "connectionString"
 	ConnectionStringSuggestionsKey = "connectionStringSuggestions"
-	OutputFileNameKey              = "outputFileName"
-	EncloseWithMermaidBackticksKey = "encloseWithMermaidBackticks"
 	DebugKey                       = "debug"
-	OmitConstraintLabelsKey        = "omitConstraintLabels"
+	EncloseWithMermaidBackticksKey = "encloseWithMermaidBackticks"
+	IgnoreTables                   = "ignoreTables"
 	OmitAttributeKeysKey           = "omitAttributeKeys"
+	OmitConstraintLabelsKey        = "omitConstraintLabels"
+	OutputFileNameKey              = "outputFileName"
+	OutputMode                     = "outputMode"
+	RelationshipLabelsKey          = "relationshipLabels"
+	SchemaKey                      = "schema"
+	SchemaPrefixSeparator          = "schemaPrefixSeparator"
+	SelectedTablesKey              = "selectedTables"
+	ShowAllConstraintsKey          = "showAllConstraints"
 	ShowDescriptionsKey            = "showDescriptions"
-	UseAllSchemasKey               = "useAllSchemas"
 	ShowSchemaPrefix               = "showSchemaPrefix"
-	SchemaPrefixSeparator          = "schemaPrefixSeparator"
-	RelationshipLabelsKey          = "relationshipLabels"
+	UseAllSchemasKey               = "useAllSchemas"
+	UseAllTablesKey                = "useAllTables"
 )
 
 type config struct{}
 
 type MermerdConfig interface {
-	ShowAllConstraints() bool
-	UseAllTables() bool
-	IgnoreTables() []string
-	Schemas() []string
 	ConnectionString() string
-	OutputFileName() string
 	ConnectionStringSuggestions() []string
-	SelectedTables() []string
-	EncloseWithMermaidBackticks() bool
 	Debug() bool
-	OmitConstraintLabels() bool
+	EncloseWithMermaidBackticks() bool
+	IgnoreTables() []string
 	OmitAttributeKeys() bool
+	OmitConstraintLabels() bool
+	OutputFileName() string
+	OutputMode() OutputModeType
+	RelationshipLabels() []RelationshipLabel
+	SchemaPrefixSeparator() string
+	Schemas() []string
+	SelectedTables() []string
+	ShowAllConstraints() bool
 	ShowDescriptions() []string
-	UseAllSchemas() bool
 	ShowSchemaPrefix() bool
-	SchemaPrefixSeparator() string
-	RelationshipLabels() []RelationshipLabel
+	UseAllSchemas() bool
+	UseAllTables() bool
 }
 
 func NewConfig() MermerdConfig {
@@ -116,3 +118,7 @@ func (c config) ShowSchemaPrefix() bool {
 func (c config) SchemaPrefixSeparator() string {
 	return viper.GetString(SchemaPrefixSeparator)
 }
+
+func (c config) OutputMode() OutputModeType {
+	return OutputModeType(viper.GetString(OutputMode))
+}

config/output_mode.go

@@ -0,0 +1,28 @@
+package config
+
+import "errors"
+
+type OutputModeType string
+
+const (
+	File   OutputModeType = "file"
+	Stdout OutputModeType = "stdout"
+)
+
+func (o *OutputModeType) String() string {
+	return string(*o)
+}
+
+func (o *OutputModeType) Set(v string) error {
+	switch v {
+	case "file", "stdout":
+		*o = OutputModeType(v)
+		return nil
+	}
+
+	return errors.New(`must be one of "file" or "stdout"`)
+}
+
+func (o *OutputModeType) Type() string {
+	return "OutputModeType"
+}

diagram/diagram.go

@@ -2,7 +2,7 @@ package diagram
 
 import (
 	_ "embed"
-	"os"
+	"io"
 	"text/template"
 
 	"github.com/sirupsen/logrus"
@@ -19,22 +19,14 @@ type diagram struct {
 }
 
 type Diagram interface {
-	Create(result *database.Result) error
+	Create(wr io.Writer, result *database.Result) error
 }
 
 func NewDiagram(config config.MermerdConfig) Diagram {
 	return diagram{config}
 }
 
-func (d diagram) Create(result *database.Result) error {
-	f, err := os.Create(d.config.OutputFileName())
-	if err != nil {
-		logrus.Error("Could not create output file", " | ", err)
-		return err
-	}
-
-	defer f.Close()
-
+func (d diagram) Create(wr io.Writer, result *database.Result) error {
 	tmpl, err := template.New("erd_template").Parse(erdTemplate)
 	if err != nil {
 		logrus.Error("Could not load template file", " | ", err)
@@ -74,7 +66,7 @@ func (d diagram) Create(result *database.Result) error {
 		Constraints:                 constraints,
 	}
 
-	if err = tmpl.Execute(f, diagramData); err != nil {
+	if err = tmpl.Execute(wr, diagramData); err != nil {
 		logrus.Error("Could not create diagram", " | ", err)
 		return err
 	}

exampleRunConfig.yaml

@@ -10,8 +10,8 @@ schema:
 # Define what tables should be used
 #useAllTables: true
 selectedTables:
-  - article
-  - label
+  - public.article
+  - public.label
 
 # Additional flags
 showAllConstraints: true
@@ -20,6 +20,7 @@ encloseWithMermaidBackticks: false
 debug: false
 omitConstraintLabels: false
 omitAttributeKeys: false
+outputMode: stdout
 showDescriptions:
   - enumValues
   - columnComments

go.mod

@@ -3,9 +3,7 @@ module github.com/KarnerTh/mermerd
 go 1.23
 
 // https://github.com/microsoft/mssql-docker/issues/895#issuecomment-2327988940
-godebug (
-	x509negativeserial=1
-)
+godebug x509negativeserial=1
 
 require (
 	github.com/AlecAivazis/survey/v2 v2.3.7

presentation/info.go

@@ -0,0 +1,14 @@
+package presentation
+
+import (
+	"github.com/KarnerTh/mermerd/config"
+	"github.com/fatih/color"
+)
+
+func ShowInfo(c config.MermerdConfig, value string) {
+	if c.OutputMode() == config.Stdout {
+		return
+	}
+
+	color.Blue(value)
+}

presentation/intro.go

@@ -3,11 +3,16 @@ package presentation
 import (
 	"fmt"
 
+	"github.com/KarnerTh/mermerd/config"
 	"github.com/fatih/color"
 	"github.com/spf13/viper"
 )
 
-func ShowIntro() {
+func ShowIntro(c config.MermerdConfig) {
+	if c.OutputMode() == config.Stdout {
+		return
+	}
+
 	color.Green(fmt.Sprintf(`
 .  ..___.__ .  ..___.__ .__ 
 |\/|[__ [__)|\/|[__ [__)|  \

presentation/outro.go

@@ -3,10 +3,15 @@ package presentation
 import (
 	"fmt"
 
+	"github.com/KarnerTh/mermerd/config"
 	"github.com/fatih/color"
 )
 
-func ShowSuccess(fileName string) {
+func ShowSuccess(c config.MermerdConfig, fileName string) {
+	if c.OutputMode() == config.Stdout {
+		return
+	}
+
 	color.Green(fmt.Sprintf(`
 
 ✓ Diagram was created successfully (%s)

readme.md

@@ -78,6 +78,7 @@ via `mermerd -h`
       --omitAttributeKeys             omit the attribute keys (PK, FK, UK)
       --omitConstraintLabels          omit the constraint labels
   -o, --outputFileName string         output file name (default "result.mmd")
+      --outputMode OutputModeType     output mode (file, stdout) (default file)
       --runConfig string              run configuration (replaces global configuration)
   -s, --schema string                 schema that should be used
       --schemaPrefixSeparator string  the separator that should be used between schema and table name (default ".")
@@ -146,6 +147,7 @@ selectedTables:
 showAllConstraints: true
 encloseWithMermaidBackticks: true
 outputFileName: "my-db.mmd"
+outputMode: stdout
 debug: true
 omitConstraintLabels: true
 omitAttributeKeys: true
@@ -181,6 +183,9 @@ mermerd -c "postgresql://user:password@localhost:5432/yourDb" -s public
 # same as previous one, but use all available tables without interaction
 mermerd -c "postgresql://user:password@localhost:5432/yourDb" -s public --useAllTables
 
+# same as previous one, but get the result in stdout instead of a file
+mermerd -c "postgresql://user:password@localhost:5432/yourDb" -s public --useAllTables --outputMode stdout
+
 # 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