Initial source commit

constraint.go

@@ -0,0 +1,59 @@
+package simpleorm
+
+import "strings"
+
+type Constraint struct {
+	Name       string
+	Type       string
+	Columns    []Column
+	RefTable   *Table
+	RefColumns []Column
+}
+
+func (c *Constraint) ToDDL() string {
+	switch c.Type {
+	case "pk":
+		return c.toPkDDL()
+	case "fk":
+		return c.toFkDDL()
+	}
+
+	return ""
+}
+
+func (c *Constraint) toPkDDL() string {
+	var ddl strings.Builder
+	ddl.WriteString("CONSTRAINT " + c.Name + " PRIMARY KEY(")
+	for i, col := range c.Columns {
+		if i != 0 {
+			ddl.WriteString(", ")
+		}
+		ddl.WriteString(col.Name)
+	}
+	ddl.WriteString(")")
+	return ddl.String()
+}
+
+func (c *Constraint) toFkDDL() string {
+	var ddl strings.Builder
+	ddl.WriteString("CONSTRAINT " + c.Name + " FOREIGN KEY(")
+
+	for i, col := range c.Columns {
+		if i != 0 {
+			ddl.WriteString(", ")
+		}
+		ddl.WriteString(col.Name)
+	}
+	ddl.WriteString(") REFERENCES " + c.RefTable.Name + "(")
+
+	for i, col := range c.RefColumns {
+		if i != 0 {
+			ddl.WriteString(", ")
+		}
+		ddl.WriteString(col.Name)
+	}
+
+	ddl.WriteString(")")
+
+	return ddl.String()
+}