Print Foreign keys for each table

cmd/cmd.go

@@ -11,6 +11,7 @@ import (
 	"github.com/go-sql-driver/mysql"
 	// We must import the mysql driver as it is required by sqlx.
 	_ "github.com/go-sql-driver/mysql"
+
 	"github.com/ntindall/sql-gen-doc/format"
 )
 
@@ -71,7 +72,12 @@ func Execute() {
 			logger.Fatalf("couldn't convert data to logical indexes: table %s. reason: %s", tableName, err)
 		}
 
-		_, err = markdown.WriteString(format.CreateTableMarkdown(tableName, table.Comment, columns, logicalIndexes))
+		foreignKeyData, err := format.GetForeignKeyDescriptions(ctx, db, tableName)
+		if err != nil {
+			logger.Fatalf("couldn't query database to fetch foreign key data: table %s. reason: %s", tableName, err)
+		}
+
+		_, err = markdown.WriteString(format.CreateTableMarkdown(tableName, table.Comment, columns, logicalIndexes, foreignKeyData))
 		if err != nil {
 			logger.Fatalf("error writing to buffer: table %s. reason: %s", tableName, err)
 		}

fixtures/expected1.md

@@ -49,6 +49,11 @@ this is a table comment
 |------------------------|---------|---------------------------|---------|
 | `PRIMARY`              | `true`  | `(company_id, person_id)` |         |
 | `fk_persons_person_id` | `false` | `(person_id)`             |         |
+#### Foreign Key
+|      KEY NAME      | TABLE NAME  | COLUMN NAME  |       REFERENCES       |
+|--------------------|-------------|--------------|------------------------|
+| `employees_ibfk_1` | `employees` | `company_id` | `companies.company_id` |
+| `employees_ibfk_2` | `employees` | `person_id`  | `persons.person_id`    |
 
 ## goose_db_version
 #### SCHEMA

fixtures/expected2.md

@@ -52,6 +52,11 @@ this is a table comment
 |------------------------|---------|---------------------------|---------|
 | `PRIMARY`              | `true`  | `(company_id, person_id)` |         |
 | `fk_persons_person_id` | `false` | `(person_id)`             |         |
+#### Foreign Key
+|      KEY NAME      | TABLE NAME  | COLUMN NAME  |       REFERENCES       |
+|--------------------|-------------|--------------|------------------------|
+| `employees_ibfk_1` | `employees` | `company_id` | `companies.company_id` |
+| `employees_ibfk_2` | `employees` | `person_id`  | `persons.person_id`    |
 
 ## goose_db_version
 #### SCHEMA

format/foreign_description.go

@@ -0,0 +1,13 @@
+package format
+
+// ForeignDescription is generated from INFORMATION_SCHEMA.KEY_COLUMN_USAGE
+type ForeignDescription struct {
+	TableName            string `db:"table_name"`
+	ColumnName           string `db:"column_name"`
+	ConstraintName       string `db:"constraint_name"`
+	ReferencedTableName  string `db:"referenced_table_name"`
+	ReferencedColumnName string `db:"referenced_column_name"`
+}
+
+// ForeignDescriptions is a set of foreign key descriptions
+type ForeignDescriptions []ForeignDescription

format/format.go

@@ -18,7 +18,7 @@ func wrapBackTicks(s string) string {
 // CreateTableMarkdown takes the name of a table in a database and a list of
 // ColumnDescription and returns a formatted markdown table with the
 // corresponding data.
-func CreateTableMarkdown(tableName string, comment string, columns []ColumnDescription, indexes []LogicalIndex) string {
+func CreateTableMarkdown(tableName string, comment string, columns []ColumnDescription, indexes []LogicalIndex, foreignKeys ForeignDescriptions) string {
 	tableMarkdown := bytes.NewBufferString(`## ` + tableName + "\n")
 
 	if comment != "" {
@@ -27,10 +27,7 @@ func CreateTableMarkdown(tableName string, comment string, columns []ColumnDescr
 
 	tableMarkdown.WriteString("#### SCHEMA\n")
 	columnsTable := tablewriter.NewWriter(tableMarkdown)
-	columnsTable.SetHeader([]string{"FIELD", "TYPE", "NULL", "KEY", "DEFAULT", "EXTRA", "COMMENT"})
-	columnsTable.SetBorders(tablewriter.Border{Left: true, Top: false, Right: true, Bottom: false})
-	columnsTable.SetAutoWrapText(false)
-	columnsTable.SetCenterSeparator("|")
+	formatTable(columnsTable, []string{"FIELD", "TYPE", "NULL", "KEY", "DEFAULT", "EXTRA", "COMMENT"})
 
 	for _, col := range columns {
 		columnsTable.Append([]string{
@@ -65,10 +62,7 @@ func CreateTableMarkdown(tableName string, comment string, columns []ColumnDescr
 		header = []string{"KEY NAME", "UNIQUE", "COLUMNS", "COMMENT", "EXPRESSION"}
 	}
 
-	indexesTable.SetHeader(header)
-	indexesTable.SetBorders(tablewriter.Border{Left: true, Top: false, Right: true, Bottom: false})
-	indexesTable.SetAutoWrapText(false)
-	indexesTable.SetCenterSeparator("|")
+	formatTable(indexesTable, header)
 
 	for _, idx := range indexes {
 		indexRow := []string{
@@ -87,9 +81,32 @@ func CreateTableMarkdown(tableName string, comment string, columns []ColumnDescr
 	// write the indexes table to the buf
 	indexesTable.Render()
 
+	if len(foreignKeys) != 0 {
+		tableMarkdown.WriteString("#### Foreign Key\n")
+		foreignKeyTable := tablewriter.NewWriter(tableMarkdown)
+		formatTable(foreignKeyTable, []string{"KEY NAME", "TABLE NAME", "COLUMN NAME", "REFERENCES"})
+
+		for _, fk := range foreignKeys {
+			foreignKeyTable.Append([]string{
+				wrapBackTicks(fk.ConstraintName),
+				wrapBackTicks(fk.TableName),
+				wrapBackTicks(fk.ColumnName),
+				wrapBackTicks(fmt.Sprintf("%s.%s", fk.ReferencedTableName, fk.ReferencedColumnName)),
+			})
+		}
+		foreignKeyTable.Render()
+	}
+
 	return tableMarkdown.String()
 }
 
+func formatTable(table *tablewriter.Table, header []string) {
+	table.SetHeader(header)
+	table.SetBorders(tablewriter.Border{Left: true, Top: false, Right: true, Bottom: false})
+	table.SetAutoWrapText(false)
+	table.SetCenterSeparator("|")
+}
+
 func insertBetweenTags(
 	file string,
 	markdown string,

format/format_test.go

@@ -1,8 +1,12 @@
 package format
 
 import (
+	"bytes"
+	"fmt"
+	"strings"
 	"testing"
 
+	"github.com/olekukonko/tablewriter"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -74,3 +78,43 @@ markdown
 		}
 	}
 }
+
+func TestRenderForeignKeys(t *testing.T) {
+
+	testForeignKeys := []ForeignDescription{
+		{
+			ConstraintName:       "fk1",
+			TableName:            "table1",
+			ColumnName:           "col1",
+			ReferencedTableName:  "reftable",
+			ReferencedColumnName: "refcol",
+		},
+	}
+
+	expected := `
+| KEY NAME | TABLE NAME | COLUMN NAME |    REFERENCES     |
+|----------|------------|-------------|-------------------|
+| ` + "`fk1`   " + ` | ` + "`table1`  " + ` | ` + "`col1`     " + ` | ` + "`reftable.refcol`" + ` |
+`
+
+	buf := &bytes.Buffer{}
+
+	foreignKeyTable := tablewriter.NewWriter(buf)
+	formatTable(foreignKeyTable, []string{"KEY NAME", "TABLE NAME", "COLUMN NAME", "REFERENCES"})
+
+	for _, fk := range testForeignKeys {
+		foreignKeyTable.Append([]string{
+			wrapBackTicks(fk.ConstraintName),
+			wrapBackTicks(fk.TableName),
+			wrapBackTicks(fk.ColumnName),
+			wrapBackTicks(fmt.Sprintf("%s.%s", fk.ReferencedTableName, fk.ReferencedColumnName)),
+		})
+	}
+
+	foreignKeyTable.Render()
+
+	actual := buf.String()
+
+	assert.Equal(t, strings.TrimLeft(expected, "\n"), strings.TrimLeft(actual, "\n"))
+
+}

format/io.go

@@ -82,6 +82,27 @@ func GetIndexDescriptions(
 	return result, nil
 }
 
+// GetForeignKeyDescriptions queries INFORMATION_SCHEMA.KEY_COLUMN_USAGE table about references information
+func GetForeignKeyDescriptions(
+	ctx context.Context,
+	db *sqlx.DB,
+	tableName string,
+) (ForeignDescriptions, error) {
+	result := []ForeignDescription{}
+
+	if err := db.SelectContext(ctx, &result,
+		`SELECT table_name AS table_name, column_name AS column_name, constraint_name AS constraint_name, referenced_table_name AS referenced_table_name, referenced_column_name AS referenced_column_name
+		FROM information_schema.key_column_usage
+		WHERE table_name = ? AND referenced_table_name IS NOT NULL
+		ORDER BY 1,2`,
+		tableName,
+	); err != nil {
+		return nil, err
+	}
+
+	return result, nil
+}
+
 // WriteToFile takes a filename and a markdown string and writes the markdown
 // to the file. If the file is annotated with markdown comments, the markdown
 // will be inserted in between the comments. e.g.

scripts/integrate.sh

@@ -28,9 +28,9 @@ had_err=0
 
 # test case 1
 log "testing create a new file"
-./bin/sql-gen-doc -dsn 'user:password@tcp(mysql:3306)/example' -o tmp/example.md
-cp tmp/example.md logs/out1.md
-if [ "$(diff --text tmp/example.md fixtures/expected1.md |& tee logs/test1.diff)" ]; then
+./bin/sql-gen-doc -dsn 'user:password@tcp(mysql:3306)/example' -o tmp/example1.md
+cp tmp/example1.md logs/out1.md
+if [ "$(diff --text tmp/example1.md fixtures/expected1.md |& tee logs/test1.diff)" ]; then
   cat tmp/example1.md
   log_error "output did not match fixture -- see logs/test1.diff"
   had_err=1