Minor refactor for view statement

parser/sql/dialect/doris/src/main/java/org/apache/shardingsphere/sql/parser/doris/visitor/statement/type/DorisDDLStatementVisitor.java

@@ -226,6 +226,7 @@ public ASTNode visitAlterView(final AlterViewContext ctx) {
     @Override
     public ASTNode visitDropView(final DropViewContext ctx) {
         DorisDropViewStatement result = new DorisDropViewStatement();
+        result.setIfExists(null != ctx.ifExists());
         result.getViews().addAll(((CollectionValue<SimpleTableSegment>) visit(ctx.viewNames())).getValue());
         return result;
     }

parser/sql/dialect/opengauss/src/main/java/org/apache/shardingsphere/sql/parser/opengauss/visitor/statement/type/OpenGaussDDLStatementVisitor.java

@@ -666,6 +666,7 @@ public ASTNode visitDropFunction(final DropFunctionContext ctx) {
     @Override
     public ASTNode visitDropView(final DropViewContext ctx) {
         OpenGaussDropViewStatement result = new OpenGaussDropViewStatement();
+        result.setIfExists(null != ctx.ifExists());
         result.getViews().addAll(((CollectionValue<SimpleTableSegment>) visit(ctx.qualifiedNameList())).getValue());
         return result;
     }

parser/sql/dialect/postgresql/src/main/java/org/apache/shardingsphere/sql/parser/postgresql/visitor/statement/type/PostgreSQLDDLStatementVisitor.java

@@ -811,6 +811,7 @@ public ASTNode visitDropGroup(final DropGroupContext ctx) {
     @Override
     public ASTNode visitDropView(final DropViewContext ctx) {
         PostgreSQLDropViewStatement result = new PostgreSQLDropViewStatement();
+        result.setIfExists(null != ctx.ifExists());
         result.getViews().addAll(((CollectionValue<SimpleTableSegment>) visit(ctx.qualifiedNameList())).getValue());
         return result;
     }

parser/sql/dialect/presto/src/main/java/org/apache/shardingsphere/sql/parser/presto/visitor/statement/type/PrestoDDLStatementVisitor.java

@@ -67,6 +67,7 @@ public ASTNode visitCreateView(final CreateViewContext ctx) {
     @Override
     public ASTNode visitDropView(final DropViewContext ctx) {
         PrestoDropViewStatement result = new PrestoDropViewStatement();
+        result.setIfExists(null != ctx.ifExists());
         result.getViews().addAll(((CollectionValue<SimpleTableSegment>) visit(ctx.viewNames())).getValue());
         return result;
     }

parser/sql/dialect/sqlserver/src/main/java/org/apache/shardingsphere/sql/parser/sqlserver/visitor/statement/type/SQLServerDDLStatementVisitor.java

@@ -490,6 +490,7 @@ public ASTNode visitDropProcedure(final DropProcedureContext ctx) {
     @Override
     public ASTNode visitDropView(final DropViewContext ctx) {
         SQLServerDropViewStatement result = new SQLServerDropViewStatement();
+        result.setIfExists(null != ctx.ifExists());
         for (ViewNameContext each : ctx.viewName()) {
             result.getViews().add((SimpleTableSegment) visit(each));
         }

parser/sql/statement/type/doris/src/main/java/org/apache/shardingsphere/sql/parser/statement/doris/ddl/DorisDropViewStatement.java

@@ -17,11 +17,17 @@
 
 package org.apache.shardingsphere.sql.parser.statement.doris.ddl;
 
+import lombok.Getter;
+import lombok.Setter;
 import org.apache.shardingsphere.sql.parser.statement.core.statement.ddl.DropViewStatement;
 import org.apache.shardingsphere.sql.parser.statement.doris.DorisStatement;
 
 /**
  * Doris drop view statement.
  */
+@Getter
+@Setter
 public final class DorisDropViewStatement extends DropViewStatement implements DorisStatement {
+
+    private boolean ifExists;
 }

parser/sql/statement/type/opengauss/src/main/java/org/apache/shardingsphere/sql/parser/statement/opengauss/ddl/OpenGaussDropViewStatement.java

@@ -17,11 +17,17 @@
 
 package org.apache.shardingsphere.sql.parser.statement.opengauss.ddl;
 
+import lombok.Getter;
+import lombok.Setter;
 import org.apache.shardingsphere.sql.parser.statement.core.statement.ddl.DropViewStatement;
 import org.apache.shardingsphere.sql.parser.statement.opengauss.OpenGaussStatement;
 
 /**
  * OpenGauss drop view statement.
  */
+@Getter
+@Setter
 public final class OpenGaussDropViewStatement extends DropViewStatement implements OpenGaussStatement {
+
+    private boolean ifExists;
 }

parser/sql/statement/type/postgresql/src/main/java/org/apache/shardingsphere/sql/parser/statement/postgresql/ddl/PostgreSQLDropViewStatement.java

@@ -17,11 +17,17 @@
 
 package org.apache.shardingsphere.sql.parser.statement.postgresql.ddl;
 
+import lombok.Getter;
+import lombok.Setter;
 import org.apache.shardingsphere.sql.parser.statement.core.statement.ddl.DropViewStatement;
 import org.apache.shardingsphere.sql.parser.statement.postgresql.PostgreSQLStatement;
 
 /**
  * PostgreSQL drop view statement.
  */
+@Getter
+@Setter
 public final class PostgreSQLDropViewStatement extends DropViewStatement implements PostgreSQLStatement {
+
+    private boolean ifExists;
 }

parser/sql/statement/type/presto/src/main/java/org/apache/shardingsphere/sql/parser/statement/presto/ddl/PrestoDropViewStatement.java

@@ -17,11 +17,17 @@
 
 package org.apache.shardingsphere.sql.parser.statement.presto.ddl;
 
+import lombok.Getter;
+import lombok.Setter;
 import org.apache.shardingsphere.sql.parser.statement.core.statement.ddl.DropViewStatement;
 import org.apache.shardingsphere.sql.parser.statement.presto.PrestoStatement;
 
 /**
  * Presto drop view statement.
  */
+@Getter
+@Setter
 public final class PrestoDropViewStatement extends DropViewStatement implements PrestoStatement {
+
+    private boolean ifExists;
 }

parser/sql/statement/type/sqlserver/src/main/java/org/apache/shardingsphere/sql/parser/statement/sqlserver/ddl/SQLServerDropViewStatement.java

@@ -17,11 +17,17 @@
 
 package org.apache.shardingsphere.sql.parser.statement.sqlserver.ddl;
 
+import lombok.Getter;
+import lombok.Setter;
 import org.apache.shardingsphere.sql.parser.statement.core.statement.ddl.DropViewStatement;
 import org.apache.shardingsphere.sql.parser.statement.sqlserver.SQLServerStatement;
 
 /**
  * SQLServer drop view statement.
  */
+@Getter
+@Setter
 public final class SQLServerDropViewStatement extends DropViewStatement implements SQLServerStatement {
+
+    private boolean ifExists;
 }