Three ways to implement MyBatisPlus data permission control

@Bean
public MybatisPlusInterceptor paginationInterceptor() {
    MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
    PaginationInnerInterceptor paginationInnerInterceptor = new PaginationInnerInterceptor();
    ();
    (1000L);
    (true);
    (paginationInnerInterceptor);
    (new CustomLineInnerInterceptor(new () {
        @Override
        public Expression getCreateUser() {
            // Write the dead admin here directly, and get it on demand            return new StringValue("admin");
        }

        @Override
        public String getCreateUserColumn() {
            return ();
        }

        @Override
        public boolean ignoreTable(String tableName) {
            //This is a case. When multiple tables need to be filtered, they can be obtained from the configuration file or static code block.            List<String> ignoreTables = ("sys_model_relation");
            //Judge whether the current table is in the filter list            return ().anyMatch(tableName::equalsIgnoreCase);
        }
    }));
    return interceptor;
}

/**
 * @description:
 * @author: SmallNorth_Lee
 * @date: 2024/5/7 15:29
 * @version: 1.0
 */
public interface DataPermissionHandler {

    /**
      * Get user ID value expression, only a single ID value is supported
      * <p>
      *
      * @return User ID value expression
      */
    Expression getCreateUser();

    /**
      * Get user field name
      * <p>
      * The default field name is: create_user
      *
      * @return User field name
      */
    default String getCreateUserColumn() {
        return "create_user";
    }

    /**
      * Judging whether to ignore the splicing multi-user conditions based on the table name
      * <p>
      * By default, you must parse and splice multi-user conditions
      *
      * @param tableName table name
      * @return Ignore whether it is ignored, true: means ignore, false: It needs to be parsed and spliced ​​with multi-user conditions
      */
    default boolean ignoreTable(String tableName) {
        return false;
    }

    /**
      * Ignore the insert user field logic
      *
      * @param columns Insert field
      * @param createUserColumn User ID field
      * @return
      */
    default boolean ignoreInsert(List&lt;Column&gt; columns, String createUserColumn) {
        return ().map(Column::getColumnName).anyMatch(i -&gt; (createUserColumn));
    }
}

/**
 * @description:
 * @author: SmallNorth_Lee
 * @date: 2024/5/7 14:14
 * @version: 1.0
 */
@Data
@NoArgsConstructor
@AllArgsConstructor
@ToString(callSuper = true)
@EqualsAndHashCode(callSuper = true)
public class CustomLineInnerInterceptor extends BaseMultiTableInnerInterceptor implements InnerInterceptor {

    private DataPermissionHandler dataPermissionHandler;

    @Override
    public void beforeQuery(Executor executor, MappedStatement ms, Object parameter, RowBounds rowBounds, ResultHandler resultHandler, BoundSql boundSql) throws SQLException {
        if ((())) {
            return;
        }
         mpBs = (boundSql);
        (parserSingle((), null));
    }

    @Override
    public void beforePrepare(StatementHandler sh, Connection connection, Integer transactionTimeout) {
         mpSh = (sh);
        MappedStatement ms = ();
        SqlCommandType sct = ();
        if (sct ==  || sct ==  || sct == ) {
            if ((())) {
                return;
            }
             mpBs = ();
            (parserMulti((), null));
        }
    }

    @Override
    protected void processSelect(Select select, int index, String sql, Object obj) {
        final String whereSegment = (String) obj;
        processSelectBody((), whereSegment);
        List<WithItem> withItemsList = ();
        if (!(withItemsList)) {
            (withItem -> processSelectBody(withItem, whereSegment));
        }
    }

    @Override
    protected void processInsert(Insert insert, int index, String sql, Object obj) {
        if ((().getName())) {
            // Filter Exit Execution            return;
        }
        List<Column> columns = ();
        if ((columns)) {
            // No processing for inserts that do not give column names            return;
        }
        String createUserColumn = ();
        if ((columns, createUserColumn)) {
            // No processing for inserts given by the given tenant column            return;
        }
        (new Column(createUserColumn));

        // fixed gitee pulls/141 duplicate update
        List<Expression> duplicateUpdateColumns = ();
        if ((duplicateUpdateColumns)) {
            EqualsTo equalsTo = new EqualsTo();
            (new StringValue(createUserColumn));
            (());
            (equalsTo);
        }

        Select select = ();
        if (select != null && (() instanceof PlainSelect)) { //fix github issue 4998 Fixed the issue of upgrading to version 4.5            ((), (String) obj);
        } else if (() != null) {
            // fixed github pull/295
            ItemsList itemsList = ();
            Expression createUser = ();
            if (itemsList instanceof MultiExpressionList) {
                ((MultiExpressionList) itemsList).getExpressionLists().forEach(el -> ().add(createUser));
            } else {
                List<Expression> expressions = ((ExpressionList) itemsList).getExpressions();
                if ((expressions)) {//fix github issue 4998 jsqlparse 4.5 batch insert ItemsList is not a MultiExpressionList, and it requires special processing                    int len = ();
                    for (int i = 0; i < len; i++) {
                        Expression expression = (i);
                        if (expression instanceof RowConstructor) {
                            ((RowConstructor) expression).getExprList().getExpressions().add(createUser);
                        } else if (expression instanceof Parenthesis) {
                            RowConstructor rowConstructor = new RowConstructor()
                                    .withExprList(new ExpressionList(((Parenthesis) expression).getExpression(), createUser));
                            (i, rowConstructor);
                        } else {
                            if (len - 1 == i) { // (?,?) TenantId is spliced ​​only when the last expre is                                (createUser);
                            }
                        }
                    }
                } else {
                    (createUser);
                }
            }
        } else {
            throw ("Failed to process multiple-table update, please exclude the tableName or statementId");
        }
    }

    /**
      * update statement processing
      */
    @Override
    protected void processUpdate(Update update, int index, String sql, Object obj) {
        final Table table = ();
        if ((())) {
            // Filter Exit Execution            return;
        }
        ArrayList<UpdateSet> sets = ();
        if (!(sets)) {
            (us -> ().forEach(ex -> {
                if (ex instanceof SubSelect) {
                    processSelectBody(((SubSelect) ex).getSelectBody(), (String) obj);
                }
            }));
        }
        ((table, (), (String) obj));
    }

    /**
      * delete statement processing
      */
    @Override
    protected void processDelete(Delete delete, int index, String sql, Object obj) {
        if ((().getName())) {
            // Filter Exit Execution            return;
        }
        (((), (), (String) obj));
    }

    /**
      * Process insert into select
      * <p>
      * Entering here means that the table that requires insert has enabled multi-tenants, and then the selected tables are started
      *
      * @param selectBody SelectBody
      */
    protected void processInsertSelect(SelectBody selectBody, final String whereSegment) {
        PlainSelect plainSelect = (PlainSelect) selectBody;
        FromItem fromItem = ();
        if (fromItem instanceof Table) {
            // fixed gitee pulls/141 duplicate update
            processPlainSelect(plainSelect, whereSegment);
            appendSelectItem(());
        } else if (fromItem instanceof SubSelect) {
            SubSelect subSelect = (SubSelect) fromItem;
            appendSelectItem(());
            processInsertSelect((), whereSegment);
        }
    }

    /**
      * Add SelectItem
      *
      * @param selectItems SelectItem
      */
    protected void appendSelectItem(List&lt;SelectItem&gt; selectItems) {
        if ((selectItems)) {
            return;
        }
        if (() == 1) {
            SelectItem item = (0);
            if (item instanceof AllColumns || item instanceof AllTableColumns) {
                return;
            }
        }
        (new SelectExpressionItem(new Column(())));
    }

    /**
      * Tenant field alias settings
      * <p>tenantId or </p>
      *
      * @param table table object
      * @return field
      */
    protected Column getAliasColumn(Table table) {
        StringBuilder column = new StringBuilder();
        // todo If you want to alias, you must alias. Modification of this logic is prohibited.        if (() != null) {
            (().getName()).append();
        }
        (());
        return new Column(());
    }

    @Override
    public void setProperties(Properties properties) {
        (properties).whenNotBlank("dataPermissionHandler",
                ClassUtils::newInstance, this::setDataPermissionHandler);
    }

    /**
      * Build tenant conditional expressions
      *
      * @param table table object
      * @param where current where conditions
      * @param whereSegment The full path of the Mapper object to which it belongs (in the original tenant interceptor function, this parameter does not need to participate in relevant judgments)
      * @return Tenant conditional expression
      * @see BaseMultiTableInnerInterceptor#buildTableExpression(Table, Expression, String)
      */
    @Override
    public Expression buildTableExpression(final Table table, final Expression where, final String whereSegment) {
        if ((())) {
            return null;
        }
        return new EqualsTo(getAliasColumn(table), ());
    }
}

        (new DataPermissionInterceptor(new MultiDataPermissionHandler() {
            @Override
            public Expression getSqlSegment(Table table, Expression where, String mappedStatementId) {
                Column aliasColumn = getAliasColumn(table);
                if (null == aliasColumn) {
                    return null;
                }
                return new EqualsTo(getAliasColumn(table), new StringValue(()));
            }
        }));

    protected Column getAliasColumn(Table table) {
        //This is a case. When multiple tables need to be filtered, they can be obtained from the configuration file or static code block.        List<String> ignoreTables = ("sys_model_relation");
        //Judge whether the current table is in the filter list        boolean match = ().anyMatch(()::equalsIgnoreCase);
        if (match) {
            return null;
        }
        StringBuilder column = new StringBuilder();
        // todo If you want to alias, you must alias. Modification of this logic is prohibited.        if (() != null) {
            (().getName()).append();
        }
        ("create_user");
        return new Column(());
    }