CN116719838B

CN116719838B - Chain type calling method based on vastbase object method in object-oriented programming

Info

Publication number: CN116719838B
Application number: CN202310771443.XA
Authority: CN
Inventors: 邢志超; 苏章艳
Original assignee: Guangzhou Mass Database Technology Co ltd
Current assignee: Guangzhou Mass Database Technology Co ltd
Priority date: 2023-06-28
Filing date: 2023-06-28
Publication date: 2025-08-15
Anticipated expiration: 2043-06-28
Also published as: CN116719838A

Abstract

The invention relates to a chained calling method and system based on vastbase object methods in object-oriented programming. The method comprises the steps of adding a new SQL engine grammar analysis rule in a grammar analysis stage of vastbase database SQL engine, wherein the grammar analysis rule is used for analyzing chained calls of an object method, constructing a grammar tree equivalent to the traditional function nested call for the grammar analysis rule, and adding a method call identifier in each layer of method call of the grammar tree for distinguishing the method call and the common function call. The method solves the problem that PL/pgSQL process language does not support chained calls, so that a user can write codes in a simpler and more visual mode. The method can reduce the use of intermediate variables, simplify the code structure and improve the readability and maintainability of codes by supporting chained calls.

Description

Chain type calling method based on vastbase object method in object-oriented programming

Technical Field

The invention belongs to the technical field of chained calling methods, and particularly relates to a chained calling method and system based on vastbase object methods in object-oriented programming.

Background

Object Oriented Programming (OOP) is a programming paradigm in which the functionality of a program is organized into a collection of objects that interact through messaging between each other. In OOP, chained calls are a common programming technique that allows multiple methods to be invoked in a row of code in succession by calling a method on an object and returning the object itself. The object-oriented programming language supporting chained calls provides appropriate syntactic and semantic support that enables developers to easily write compact and readable code using chained calls. Through reasonable application of the chained call technology, maintainability and expandability of codes can be improved, and development efficiency is improved.

The current vastbase database enhances type functionality, supports object-oriented, allows creation of member variables and member methods, and enables invocation of object member methods using object types in the PL/pgSQL procedural language. Compared with chained calls of an object method, the traditional function call mode adopted by vastbase has the following defects that (1) redundant variables are adopted, when continuous calls are required to be carried out on a plurality of functions, the traditional writing method needs to use intermediate variables to save the result of each function call, so that a large number of redundant variables appear in codes, the readability and the simplicity of the codes are reduced, and (2) the intuitiveness is lacking, the traditional vastbase grammar requires that each function call needs to be explicitly provided with parameters in brackets, so that the hierarchical structure of the codes is not visual enough, and the sequence and the relation of the function calls are difficult to be quickly understood. Accordingly, there is a need to provide a solution to support chained calls of object methods to refine the object-oriented programming paradigm of vastbase.

In addition, the syntax of the PL/pgSQL procedural language does not support chained calls, so to support the call chain of function methods, one possible solution is to define a processor function whose parameters are strings of the function call chain, and the function of the function is to convert the function call chain string into a conventional function call manner and execute it. The scheme has the advantages of convenient implementation, no need of modifying the grammar of PL/pgSQL, no simplicity and intuitiveness, and the processor method must be called each time the chained call is required to be implemented. Thus, to perfectly support chained calls to object methods, new grammar rules need to be designed and defined to support the functional form of chained calls in the PL/pgSQL procedural language.

Disclosure of Invention

In order to solve the problem that PL/pgSQL process language does not support chained calls, the invention provides a method for realizing function call in the form of object.m1 (args 1) m2 (args 2) in PL/pgSQL process language of vastbase database, so that a user can write codes in a simpler and more visual manner. The method of the invention can reduce the use of intermediate variables, simplify the code structure and improve the readability and maintainability of codes by supporting chained calls.

Interpretation of the terms

Vastbase database vastbase database is an enterprise-level relational database with mass data developed based on open source OpenGauss kernel, wherein vastbase supports creation of object types and creates constructors, member attributes, member methods and static methods in the object types in a compatible mode.

Chained calls are a programming style that allows complex chains of operations to be built by using point operators consecutively between method calls. In chained calls, each method call returns an object, which can in turn continue to call other methods, forming a chained call sequence.

PL/pgSQL PL/pgSQL is a programming language that can be used to write stored procedures, triggers, functions and anonymous code blocks in the vastbase database, which is a built-in extension language provided by vastbase for extending the functionality and flexibility of the database.

SQL engine is a highly optimized and function-rich core component of vastbase database, has the functions of lexical grammar analysis, semantic analysis, query optimization and the like, and is a module responsible for analyzing, optimizing and executing SQL query.

Object oriented support vastbase the database enhances creation of type types, supports object oriented programming, allows creation of member variables and member methods, and enables invocation of object member methods using object types in the PL/pgSQL procedural language. The member method of an object is as usual in the pg_proc system table, but the value of protypekind is m indicating that the function is a member method and the type of the first parameter is an object type, which parameter needs to be omitted when called in object form.

The invention uses PL/pgSQL, SQL engine and object oriented support function in vastbase database to enhance grammar of method function call and support chained call of object method.

The collaborative workflow of PL/pgSQL and SQL engine for object method invocation of vastbase database is shown in FIG. 1, comprising the steps of:

the PL/pgSQL lexical parser receives the input code statement (for example obj. M (args)) and invokes the SQL engine lexical parser to parse the code.

The lexical analyzer of the SQL engine decomposes the code into a series of lexical units and performs corresponding lexical analysis and processing.

And 3, performing corresponding processing on lexical units returned by the SQL engine by the PL/pgSQL lexical analyzer, such as prospectively caching the lexical analysis result of the SQL engine and the like.

And 4, the PL/pgSQL grammar parser parses according to an output lexical unit of the lexical parser, and verifies and constructs a grammar tree by matching with corresponding grammar rules so as to understand the structure and the semantics of the codes, constructs corresponding SQL sentences and transmits the SQL sentences to the SQL engine. In this process, the syntax parsing process will determine if the type of obj is an object type, if m is a member function, and if both are in compliance will convert the call in the form of obj.m (args) into a SQL statement of select m (obj, args).

The SQL engine analyzes, optimizes and executes SQL query and the like on the SQL statement transmitted by the PL/pgSQL.

As can be seen from the above flow, the call obj.m (args) of the object method is finally implemented by converting into a conventional function call m (obj, args). Thus, we consider that this chained syntax can be implemented at the bottom by converting object method chained calls into legacy function nested calls, such as an obj.m1 (args 1) m2 (args) call into m2 (m 1 (obj, args 1), args 2) call. To achieve this, there are generally two schemes:

1. Chained calls to object methods are converted to function nest calls in the PL/pgSQL syntax parsing stage, such as SQL statements converting obj.m1 (args) m2 (args) to select m2 (m 1 (obj, args 1), args 2). However, the syntax parsing of PL/pgSQL is more converting a programming statement into an SQL statement, so for this scheme the SQL engine will not be able to distinguish whether the statement itself is a function call or an object method call. If the chained call method is a normal function and not a member method, but is not known to be chained call in the semantic parsing stage of the SQL engine, the examination is avoided, and the wrong usage is generated (the normal function should not support chained call). So the semantic checking of common function misuse chained calls also needs to be placed in the syntax parsing stage of PL/pgSQL, which will increase the difficulty of syntax semantic parsing.

2. A new SQL engine syntax parsing rule is added, which is used to parse chained calls of object methods and construct a syntax tree equivalent to traditional function nested calls, such as obj.m1 (args 1) m2 (args 2), and a syntax tree equivalent to m2 (m 1 (obj, args 1), args 2) call rules is constructed. However, due to the naming resolution rules of vastbase, the function call expression may consist of a schema name (schema) and a function name (function), namely schema. Function (args), and thus the syntax resolution tool bison of vastbase may generate move-in-specification conflicts with the function expression schema. Function (args) syntax (both in the form of identifier and identifier ()) when resolving the object method chained syntax obj. M1 (args 1).

In summary, it can be seen that the scheme 1 increases the difficulty of semantic parsing, and the grammar implementation of the scheme 2 is difficult. Therefore, we consider that a new grammar implementation method for chained invocation of the object method is constructed by combining scheme 1 and scheme 2 on the basis of parsing obj.m (arg) flow (as shown in fig. 1), and the specific flow of the method is shown in fig. 3. In the syntax parsing stage of PL/pgSQL, only the first layer of the conversion object method chaining call is parsed, such as the SQL statement that converts obj.m1 (args) m2 (args 2) statements into select m1 (obj, args 1) m2 (args 2) only. Then, in the syntax parsing stage of the SQL engine, a syntax parsing rule as shown in fig. 4 is added, the rule constructs a syntax tree equivalent to the conventional function nesting call, and an identifier is added in each layer of method call of the syntax tree to distinguish the method call from the normal function call, for example, for m1 (obj, args 1) m2 (args 2) expression, a syntax tree equivalent to m2 (m 1 (obj, args 1) args 2) is constructed. The scheme of the invention has simple semantic analysis, can distinguish whether the method is called or the common function is called by only one identifier, has simple grammar realization, and can complete conversion by splicing the method calls only on the basis of analyzing obj.m1 (args) by PL/pgSQL (the flow of figure 1). In addition, through simple processing of PL/pgSQL, the scheme can uniformly analyze chained calls in the form of function (args) m1 (args 1) and obj.m1 (args) m2 (args 2) without other processing.

Specifically, the invention provides a chained call method based on an object method in vastbase object-oriented programming, which aims to enable a Vastbase database to support chained call on the basis of supporting object-oriented, and comprises the steps of adding a new SQL engine grammar analysis rule in a grammar analysis stage of an SQL engine of a vastbase database, wherein the grammar analysis rule is used for analyzing chained call of the object method, constructing a grammar tree equivalent to traditional function nested call for the grammar analysis rule, and adding a method call identifier in each layer of method call of the grammar tree, wherein the identifier is used for distinguishing the method call and the common function call.

In a first aspect, the present invention provides a chained call method for a user to chained call member methods of objects in a PL/pgSQL process language of a Vastbase database based on a chained call method for object methods in vastbase object-oriented programming, the method comprising the steps of:

the S1.PL/pgSQL module converts an obj.m1 (args 1) statement into m1 (obj, args 1) on the basis of object call, then splices a subsequent method.m2 (args 2), constructs an SQL statement of m1 (obj, args 1) m2 (args 2), and transmits the SQL statement into an SQL engine;

S2, adding a new SQL engine grammar analysis rule, constructing a grammar tree equivalent to m2 (m 1 (obj, args 1) and args 2) for m1 (obj, args 1) and m2 (args) sentences, converting each method call into a node in the grammar tree, and adding a method call identifier in each layer of method call of the grammar tree;

S3, traversing each function call node to verify in a semantic analysis stage, checking whether the node has a corresponding function for each function call node, verifying whether the node is a method call, if the node is a method call, continuing to verify whether the node is a member method, if so, taking out a first parameter node, and repeating the judgment until the first parameter node is not the function node;

S4, starting from the last node, executing the function according to the logic of the nested call, for each function call node, transmitting the function call result to the function call of the upper layer as the first parameter, sequentially executing the function call upwards, finally obtaining the result of the whole method call chain, and returning the result to the caller.

Further, the method is based on vastbase that the method expression of the SQL engine grammar parsing rule added in the step S2 of the chained calling method of the object method in the object-oriented programming is composed of one function call plus one method chain, and the method chain is composed of a plurality of method calls.

Further, the connection sequence of the function nodes in the grammar tree in the chained call method step S2 of the object method in the object-oriented programming based on vastbase is the same as the sequence in the SQL sentence.

Further, in step S3 of the chained call method of the object method in the object-oriented programming based on vastbase, if the function corresponding to a certain function call node is checked and found to be absent or verified, the certain function call node is found to be a method call but not a member method, the invention performs error reporting processing.

Further, the chained call method based on the object method in vastbase object-oriented programming can uniformly analyze chained calls in the form of function (args) m1 (args 1) and the form of obj.m1 (args) m2 (args 2).

In a second aspect, the present invention provides a chained call system based on vastbase object methods in object-oriented programming, the system comprising:

the statement processing module is used for converting and splicing the forms of object method function statements;

The rule management module is used for adding a new SQL engine grammar analysis rule, constructing a grammar tree for function nesting and calling by utilizing the new rule, and adding a method call identifier in each layer of method call of the grammar tree;

the checking and verifying module is used for checking whether the function call node has a corresponding function, is a method call and is a member method;

and the function execution module is used for executing the functions layer by layer from bottom to top according to the logic of the nested call.

Further, the new SQL engine grammar parsing rule method expression added by the rule management module in the chained call system based on the object method in vastbase object-oriented programming is composed of one function call plus one method chain, and the method chain is composed of a plurality of method calls.

Finally, the present invention also provides a computer readable storage medium, where a computer program is stored, where the program, when executed by a processor, implements the steps of the chained call method based on the object method in vastbase object-oriented programming.

In summary, the chained calling method based on vastbase object methods in object-oriented programming has the following characteristics:

(1) The invention provides a method for realizing function call in the form of object.m1 (args) m2 (args) in the PL/pgSQL process language of vastbase database, which solves the problem that the PL/pgSQL process language does not support chained call, so that a user can write codes in a simpler and more visual mode.

(2) The method of the invention can reduce the use of intermediate variables, simplify the code structure and improve the readability and maintainability of codes by supporting chained calls.

(3) The method has simple semantic analysis, can distinguish the method call and the common function call only by one identifier, has simple grammar realization, and can complete conversion by splicing the subsequent method call on the basis of PL/pgSQL analyzing obj.m1 (args).

(4) Through simple PL/pgSQL processing, the method can uniformly analyze chained calls in the form of function (args) m1 (args 1) and obj.m1 (args) m2 (args 2).

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that need to be used in the embodiments of the present invention will be briefly described below, and it is obvious that the following drawings are only some embodiments described in the present invention, and other drawings can be obtained according to the drawings without inventive effort for those skilled in the art.

FIG. 1 is a collaborative workflow diagram of PL/pgSQL and SQL engine of vastbase databases for object method invocation in the present invention, taking obj.m (args) as an example.

FIG. 2 is a flow chart of the method chained call method of the present invention.

FIG. 3 is a collaborative workflow diagram of PL/pgSQL and SQL engine of vastbase databases for chained invocation of object methods in the present invention, for example obj.m1 (args) m2 (args).

FIG. 4 is a schematic diagram of the SQL engine grammar parsing rules of the present invention vastbase database.

FIG. 5 is a block diagram of the components of the subject method chained call system.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments and corresponding drawings. It is apparent that the described embodiments are only some embodiments of the present invention, but not all embodiments, and the present invention may be implemented or applied by different specific embodiments, and that various modifications or changes may be made in the details of the present description based on different points of view and applications without departing from the spirit of the present invention.

Meanwhile, it should be understood that the scope of the present invention is not limited to the following specific embodiments, and it should be further understood that the terminology used in the examples of the present invention is for the purpose of describing the specific embodiments, and is not intended to limit the scope of the present invention.

Embodiment 1A chain type calling method based on vastbase object methods in object-oriented programming

The technical scheme of the invention is described below with reference to the accompanying drawings.

The method aims at providing the user with a member method for chained calling objects in the PL/pgSQL process language of Vastbase database, and the processing flow of the method is as follows (for example, obj.m1 (args) m2 (args 2)), and the specific flow is shown in fig. 2 and 3.

The PL/pgSQL module converts the obj.m1 (args 1) statement into m1 (obj, args 1) on the basis of the object call, then concatenates the subsequent method.m2 (args 2), finally constructs the SQL statement of m1 (obj, args 1) m2 (args 2), and passes into the SQL engine.

2. In the grammar analysis stage, a new SQL engine grammar analysis rule is added, the newly added SQL engine grammar analysis rule is shown in fig. 4, the method expression is composed of a function call plus a method chain, and the method chain is composed of a plurality of method calls. The rule constructs a syntax tree equivalent to m2 (m 1 (obj, args 1), args 2) for the m1 (obj, args 1) m2 (args) statement, converts each method call into a node in the syntax tree, and adds a method call identifier to each layer of method call in the syntax tree, indicating that it is a method call operation. Wherein the order of connection of the syntax tree function nodes of m1 (obj, args 1) m2 (args 2) is the same as the order of m2 (m 1 (obj, args 1), args 2).

3. In the semantic analysis stage, each function call node is traversed to carry out verification, whether the corresponding function exists in the node or not is checked for each function call node, whether the node is a method call or not is verified, if the node is a method call, whether the node is a member method or not is continuously verified, if the node is the method call, the first parameter node is taken out to repeat the judgment until the first parameter node is not the function node, if the function corresponding to a certain function call node is checked to be not exist or the function call node is verified to be found to be the method call but not the member method, error processing is carried out, and the method call cannot be executed. As in this example, it is necessary to verify whether there is a function of m2, whether the function node of m2 is a method call, and if so, whether m2 is a member method. If m 3's method call also exists after m2, m3 also needs to be validated next. It should be noted that m1 has been verified in the PL/pgSQL syntax parsing stage (see FIG. 1).

4. Starting from the last node, executing the function according to the logic of the nested call, for each function call node, transmitting the result of the function call to the function call of the upper layer as the first parameter, and sequentially executing the function call upwards to finally obtain the result of the whole method call chain, and returning the result to the caller. In this example, the m1 method is executed first, then the execution result of the m1 method is used as the first parameter of the m2 method to call the m2 method continuously, and the final result is returned.

Embodiment 2A chain call System based on vastbase object methods in object-oriented Programming

Referring to fig. 5, the present system includes:

The modules operate according to the chained calling method based on the object method in vastbase object-oriented programming.

The foregoing is merely exemplary of the present invention and is not intended to limit the present invention. Various modifications and variations of the present invention will be apparent to those skilled in the art. Any modification, replacement, etc. that comes within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A chained call method based on object methods in vastbase object-oriented programming is characterized in that the method comprises the steps of adding a new SQL engine grammar analysis rule in a grammar analysis stage of a vastbase database SQL engine, wherein the grammar analysis rule is used for analyzing chained calls of the object methods, constructing a grammar tree equivalent to traditional function nested calls for the grammar rule, and adding a method call identifier in each layer of method call of the grammar tree, wherein the identifier is used for distinguishing the method call and the common function call;

The method comprises the following steps:

The PL/pgSQL module converts the obj.m1 (args 1) statement into m1 (obj, args 1), then splices the subsequent method.m2 (args 2) to construct an SQL statement of m1 (obj, args 1) m2 (args 2) and transmits the SQL statement into an SQL engine;

S2, adding a new SQL engine grammar analysis rule, wherein the rule constructs a grammar tree equivalent to m2 (m 1 (obj, args 1) and args 2) for m1 (obj, args 1) m2 (args) sentences, converts each method call into nodes in the grammar tree, and adds a method call identifier in each layer of method call of the grammar tree;

S4, starting from the last node, executing the function according to the logic of the nested call, for each function call node, transmitting the result of the function call to the function call of the upper layer as the first parameter, sequentially executing the function call upwards, finally obtaining the result of the whole method call chain, and returning the result to the caller.

2. The chained call method of claim 1 based on vastbase object methods in object-oriented programming, wherein the new SQL engine syntax parsing rule method expression in step S2 is composed of one function call plus one method chain composed of a plurality of method calls.

3. The chained call method of claim 1 based on vastbase object-oriented programming method, wherein the order of connection of function nodes in the syntax tree in step S2 is the same as the order in SQL statements.

4. The chained call method of claim 1 based on vastbase object methods in object-oriented programming, wherein in step S3, if checking that a function corresponding to a function call node does not exist or verifying that a function call node is a method call but not a member method is found, an error is reported.

5. The chained call method based on vastbase object methods in object-oriented programming according to claim 1, wherein the chained call method of the object methods can uniformly parse chained calls in the form of function (args) m1 (args 1) and obj.m1 (args) m2 (args 2).

6. A chained call system based on vastbase object-oriented programming method, characterized in that the system is run to implement the steps of the chained call method based on vastbase object-oriented programming method according to any one of claims 1 to 5;

The system comprises:

7. A computer readable storage medium having stored thereon a computer program which when executed by a processor implements the steps of the chained invocation method of the object method in vastbase-based object oriented programming of any of claims 1-5.