Merge pull request #862 from h2database/constraint_type_enum

Convert constraint type into enum

h2/src/main/org/h2/command/ddl/AlterTableAddConstraint.java

@@ -120,7 +120,7 @@ public class AlterTableAddConstraint extends SchemaCommand {
             ArrayList<Constraint> constraints = table.getConstraints();
             for (int i = 0; constraints != null && i < constraints.size(); i++) {
                 Constraint c = constraints.get(i);
-                if (Constraint.PRIMARY_KEY.equals(c.getConstraintType())) {
+                if (Constraint.Type.PRIMARY_KEY == c.getConstraintType()) {
                     throw DbException.get(ErrorCode.SECOND_PRIMARY_KEY);
                 }
             }

h2/src/main/org/h2/command/ddl/DropIndex.java

@@ -57,7 +57,7 @@ public class DropIndex extends SchemaCommand {
                 Constraint cons = constraints.get(i);
                 if (cons.usesIndex(index)) {
                     // can drop primary key index (for compatibility)
-                    if (Constraint.PRIMARY_KEY.equals(cons.getConstraintType())) {
+                    if (Constraint.Type.PRIMARY_KEY == cons.getConstraintType()) {
                         pkConstraint = cons;
                     } else {
                         throw DbException.get(

h2/src/main/org/h2/command/dml/ScriptCommand.java

@@ -284,8 +284,7 @@ public class ScriptCommand extends ScriptBase {
                 final ArrayList<Constraint> constraints = table.getConstraints();
                 if (constraints != null) {
                     for (Constraint constraint : constraints) {
-                        if (Constraint.PRIMARY_KEY.equals(
-                                constraint.getConstraintType())) {
+                        if (Constraint.Type.PRIMARY_KEY == constraint.getConstraintType()) {
                             add(constraint.getCreateSQLWithoutIndexes(), false);
                         }
                     }
@@ -336,7 +335,7 @@ public class ScriptCommand extends ScriptBase {
                 if (constraint.getTable().isHidden()) {
                     continue;
                 }
-                if (!Constraint.PRIMARY_KEY.equals(constraint.getConstraintType())) {
+                if (Constraint.Type.PRIMARY_KEY != constraint.getConstraintType()) {
                     add(constraint.getCreateSQLWithoutIndexes(), false);
                 }
             }

h2/src/main/org/h2/constraint/Constraint.java

@@ -24,25 +24,24 @@ import org.h2.table.Table;
 public abstract class Constraint extends SchemaObjectBase implements
         Comparable<Constraint> {
 
-    /**
-     * The constraint type name for check constraints.
-     */
-    public static final String CHECK = "CHECK";
-
-    /**
-     * The constraint type name for referential constraints.
-     */
-    public static final String REFERENTIAL = "REFERENTIAL";
-
-    /**
-     * The constraint type name for unique constraints.
-     */
-    public static final String UNIQUE = "UNIQUE";
-
-    /**
-     * The constraint type name for primary key constraints.
-     */
-    public static final String PRIMARY_KEY = "PRIMARY KEY";
+    public enum Type {
+        /**
+         * The constraint type for check constraints.
+         */
+        CHECK,
+        /**
+         * The constraint type for primary key constraints.
+         */
+        PRIMARY_KEY,
+        /**
+         * The constraint type for unique constraints.
+         */
+        UNIQUE,
+        /**
+         * The constraint type for referential constraints.
+         */
+        REFERENTIAL
+    }
 
     /**
      * The table for which this constraint is defined.
@@ -60,7 +59,7 @@ public abstract class Constraint extends SchemaObjectBase implements
      *
      * @return the name
      */
-    public abstract String getConstraintType();
+    public abstract Type getConstraintType();
 
     /**
      * Check if this row fulfils the constraint.
@@ -155,29 +154,12 @@ public abstract class Constraint extends SchemaObjectBase implements
         return null;
     }
 
-    private int getConstraintTypeOrder() {
-        String constraintType = getConstraintType();
-        if (CHECK.equals(constraintType)) {
-            return 0;
-        } else if (PRIMARY_KEY.equals(constraintType)) {
-            return 1;
-        } else if (UNIQUE.equals(constraintType)) {
-            return 2;
-        } else if (REFERENTIAL.equals(constraintType)) {
-            return 3;
-        } else {
-            throw DbException.throwInternalError("type: " + constraintType);
-        }
-    }
-
     @Override
     public int compareTo(Constraint other) {
         if (this == other) {
             return 0;
         }
-        int thisType = getConstraintTypeOrder();
-        int otherType = other.getConstraintTypeOrder();
-        return thisType - otherType;
+        return Integer.compare(getConstraintType().ordinal(), other.getConstraintType().ordinal());
     }
 
     @Override

h2/src/main/org/h2/constraint/ConstraintCheck.java

@@ -36,8 +36,8 @@ public class ConstraintCheck extends Constraint {
     }
 
     @Override
-    public String getConstraintType() {
-        return Constraint.CHECK;
+    public Type getConstraintType() {
+        return Constraint.Type.CHECK;
     }
 
     public void setTableFilter(TableFilter filter) {

h2/src/main/org/h2/constraint/ConstraintReferential.java

@@ -50,8 +50,8 @@ public class ConstraintReferential extends Constraint {
     }
 
     @Override
-    public String getConstraintType() {
-        return Constraint.REFERENTIAL;
+    public Type getConstraintType() {
+        return Constraint.Type.REFERENTIAL;
     }
 
     private static void appendAction(StatementBuilder buff, ConstraintActionType action) {

h2/src/main/org/h2/constraint/ConstraintUnique.java

@@ -34,8 +34,8 @@ public class ConstraintUnique extends Constraint {
     }
 
     @Override
-    public String getConstraintType() {
-        return primaryKey ? Constraint.PRIMARY_KEY : Constraint.UNIQUE;
+    public Type getConstraintType() {
+        return primaryKey ? Constraint.Type.PRIMARY_KEY : Constraint.Type.UNIQUE;
     }
 
     @Override

h2/src/main/org/h2/mvstore/db/MVTable.java

@@ -467,7 +467,7 @@ public class MVTable extends TableBase {
             if (constraints != null) {
                 for (int i = 0, size = constraints.size(); i < size; i++) {
                     Constraint c = constraints.get(i);
-                    if (!(c.getConstraintType().equals(Constraint.REFERENTIAL))) {
+                    if (c.getConstraintType() != Constraint.Type.REFERENTIAL) {
                         continue;
                     }
                     ConstraintReferential ref = (ConstraintReferential) c;

h2/src/main/org/h2/table/MetaTable.java

@@ -868,8 +868,7 @@ public class MetaTable extends Table {
                         Constraint constraint = constraints.get(k);
                         if (constraint.usesIndex(index)) {
                             if (index.getIndexType().isPrimaryKey()) {
-                                if (constraint.getConstraintType().equals(
-                                        Constraint.PRIMARY_KEY)) {
+                                if (constraint.getConstraintType() == Constraint.Type.PRIMARY_KEY) {
                                     constraintName = constraint.getName();
                                 }
                             } else {
@@ -1544,7 +1543,7 @@ public class MetaTable extends Table {
             for (SchemaObject obj : database.getAllSchemaObjects(
                     DbObject.CONSTRAINT)) {
                 Constraint constraint = (Constraint) obj;
-                if (!(constraint.getConstraintType().equals(Constraint.REFERENTIAL))) {
+                if (constraint.getConstraintType() != Constraint.Type.REFERENTIAL) {
                     continue;
                 }
                 ConstraintReferential ref = (ConstraintReferential) constraint;
@@ -1597,7 +1596,7 @@ public class MetaTable extends Table {
             for (SchemaObject obj : database.getAllSchemaObjects(
                     DbObject.CONSTRAINT)) {
                 Constraint constraint = (Constraint) obj;
-                String constraintType = constraint.getConstraintType();
+                Constraint.Type constraintType = constraint.getConstraintType();
                 String checkExpression = null;
                 IndexColumn[] indexColumns = null;
                 Table table = constraint.getTable();
@@ -1613,12 +1612,12 @@ public class MetaTable extends Table {
                 if (!checkIndex(session, tableName, indexFrom, indexTo)) {
                     continue;
                 }
-                if (constraintType.equals(Constraint.CHECK)) {
+                if (constraintType == Constraint.Type.CHECK) {
                     checkExpression = ((ConstraintCheck) constraint).getExpression().getSQL();
-                } else if (constraintType.equals(Constraint.UNIQUE) ||
-                        constraintType.equals(Constraint.PRIMARY_KEY)) {
+                } else if (constraintType == Constraint.Type.UNIQUE ||
+                           constraintType == Constraint.Type.PRIMARY_KEY) {
                     indexColumns = ((ConstraintUnique) constraint).getColumns();
-                } else if (constraintType.equals(Constraint.REFERENTIAL)) {
+                } else if (constraintType == Constraint.Type.REFERENTIAL) {
                     indexColumns = ((ConstraintReferential) constraint).getColumns();
                 }
                 String columnList = null;
@@ -1638,7 +1637,7 @@ public class MetaTable extends Table {
                         // CONSTRAINT_NAME
                         identifier(constraint.getName()),
                         // CONSTRAINT_TYPE
-                        constraintType,
+                        constraintType.toString(),
                         // TABLE_CATALOG
                         catalog,
                         // TABLE_SCHEMA

h2/src/main/org/h2/table/RegularTable.java

@@ -746,7 +746,7 @@ public class RegularTable extends TableBase {
             if (constraints != null) {
                 for (int i = 0, size = constraints.size(); i < size; i++) {
                     Constraint c = constraints.get(i);
-                    if (!(c.getConstraintType().equals(Constraint.REFERENTIAL))) {
+                    if (c.getConstraintType() != Constraint.Type.REFERENTIAL) {
                         continue;
                     }
                     ConstraintReferential ref = (ConstraintReferential) c;