KDb

KDbParser.h
1/* This file is part of the KDE project
2 Copyright (C) 2003 Lucijan Busch <lucijan@kde.org>
3 Copyright (C) 2004-2018 Jarosław Staniek <staniek@kde.org>
4
5 This library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Library General Public
7 License as published by the Free Software Foundation; either
8 version 2 of the License, or (at your option) any later version.
9
10 This library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Library General Public License for more details.
14
15 You should have received a copy of the GNU Library General Public License
16 along with this library; see the file COPYING.LIB. If not, write to
17 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
18 * Boston, MA 02110-1301, USA.
19*/
20
21#ifndef KDB_PARSER_H
22#define KDB_PARSER_H
23
24#include "kdb_export.h"
25
26#include <QString>
27#include <QCoreApplication>
28
29class KDbConnection;
30class KDbQuerySchema;
31class KDbTableSchema;
33
34/**
35 * Provides detailed error description about KDbParser.
36 *
37 * @todo Make it explicitly shared using SDC
38 * @todo change type to enum
39 */
40class KDB_EXPORT KDbParserError
41{
42public:
43 /**
44 * Empty constructor.
45 */
47
48 /**
49 * Constructor.
50 *
51 * @param type The error type.
52 * @param message A description of the error.
53 * @param token Token where the Error happend.
54 * @param position The position where the error happened.
55 */
56 KDbParserError(const QString &type, const QString &message, const QByteArray &token, int position);
57
58 /**
59 * Copy constructor.
60 */
61 KDbParserError(const KDbParserError &other);
62
64
65 KDbParserError& operator=(const KDbParserError &other);
66
67 bool operator==(const KDbParserError &other) const;
68
69 inline bool operator!=(const KDbParserError &other) const { return !operator==(other); }
70
71 /**
72 * @return the error type.
73 */
74 QString type() const;
75
76 /**
77 * @return translated error message.
78 */
79 QString message() const;
80
81 /**
82 * @return (character) position where the error happened.
83 */
84 int position() const;
85
86private:
87 class Private;
88 Private * const d;
89};
90
91class KDbParserPrivate; //!< @internal
92
93/**
94 * A parser tool for SQL statements.
95 *
96 * The KDbParser class offers functionality of a SQL parser for database-backend-independent
97 * KDbSQL dialect. Schema objects such as KDbQuerySchema that are created after successful parsing
98 * can be then used for running the queries on actual data or used for further modification.
99 *
100 * @todo Add examples
101 * @todo Support more types than the SELECT
102 */
103class KDB_EXPORT KDbParser
104{
105 Q_DECLARE_TR_FUNCTIONS(KDbParser)
106public:
107
108 /**
109 * The type of the statement.
110 */
112 NoType, //!< No statement type specified or detected
113 Select, //!< Query-statement
114 CreateTable, //!< Create a new table
115 AlterTable, //!< Alter schema of an existing table
116 Insert, //!< Insert new records
117 Update, //!< Update existing records
118 Delete //!< Delete existing records
119 };
120
121 /**
122 * Constructs an new parser object.
123 * @a connection is used to obtain context, for example wildcards "T.*" resolution
124 * is possible only if information about table T is available.
125 */
126 explicit KDbParser(KDbConnection *connection);
127
128 ~KDbParser();
129
130 /**
131 * @brief Clears the parser's status and runs the parsing for a raw SQL statement
132 *
133 * If parsing of @a sql results in a proper query and @a query is present, it will be set to
134 * representation of the parsed query.
135 * @since 3.1
136 */
137 bool parse(const KDbEscapedString &sql, KDbQuerySchema *query = nullptr);
138
139 /**
140 * Reset the parser's status (table, query, error, statement, statement type).
141 */
142 void reset();
143
144 /**
145 * @return the resulting statement type
146 * NoType is returned if parsing failed or it has not been yet performed or reset() was called.
147 */
148 StatementType statementType() const;
149
150 /**
151 * @return the resulting statement type as string. It is not translated.
152 */
153 QString statementTypeString() const;
154
155 /**
156 * @return a pointer to a query schema if 'CREATE TABLE ...' statement was parsed
157 * or @c nullptr for any other statements or on error.
158 * @note A proper table schema is returned only once for each successful parse() call,
159 * and the object is owned by the caller. In all other cases @c nullptr is returned.
160 *
161 * @todo Implement this
162 */
163 Q_REQUIRED_RESULT KDbTableSchema *table();
164
165 /**
166 * @return a pointer to a new query schema created by parsing 'SELECT ...' statement
167 * or @c nullptr for any other statements or on error.
168 * If existing query was supplied to parse() @c nullptr is returned.
169 * @note A proper query schema is returned only once for each successful parse() call,
170 * and the object is owned by the caller. In all other cases nullptr is returned.
171 */
172 Q_REQUIRED_RESULT KDbQuerySchema *query();
173
174 /**
175 * @return a pointer to the used database connection or @c nullptr if it was not set.
176 */
177 KDbConnection *connection();
178
179 //! @overload
180 //! @since 3.1
181 const KDbConnection *connection() const;
182
183 /**
184 * @return detailed information about last error.
185 * If no error occurred KDbParserError::type() is empty.
186 */
187 KDbParserError error() const;
188
189 /**
190 * @return the statement passed on the most recent call of parse().
191 */
192 KDbEscapedString statement() const;
193
194private:
195 void init();
196
197 friend class KDbParserPrivate;
198 KDbParserPrivate * const d; //!< @internal d-pointer class.
199 Q_DISABLE_COPY(KDbParser)
200};
201
202//! Sends information about parser error @a error to debug output @a dbg.
203KDB_EXPORT QDebug operator<<(QDebug dbg, const KDbParserError& error);
204
205#endif
Provides database connection, allowing queries and data modification.
Specialized string for escaping.
Provides detailed error description about KDbParser.
Definition KDbParser.h:41
A parser tool for SQL statements.
Definition KDbParser.h:104
StatementType
The type of the statement.
Definition KDbParser.h:111
@ Update
Update existing records.
Definition KDbParser.h:117
@ Insert
Insert new records.
Definition KDbParser.h:116
@ AlterTable
Alter schema of an existing table.
Definition KDbParser.h:115
@ NoType
No statement type specified or detected.
Definition KDbParser.h:112
@ Select
Query-statement.
Definition KDbParser.h:113
@ CreateTable
Create a new table.
Definition KDbParser.h:114
KDbQuerySchema provides information about database query.
QDebug operator<<(QDebug dbg, const PerceptualColor::LchaDouble &value)
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