1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302 | -----------------------------------------------------------------------
-- ADO Parameters -- Parameters for queries
-- Copyright (C) 2010, 2011, 2012, 2013, 2015, 2017, 2019, 2022 Stephane Carrez
-- Written by Stephane Carrez (Stephane.Carrez@gmail.com)
--
-- Licensed under the Apache License, Version 2.0 (the "License");
-- you may not use this file except in compliance with the License.
-- You may obtain a copy of the License at
--
-- http://www.apache.org/licenses/LICENSE-2.0
--
-- Unless required by applicable law or agreed to in writing, software
-- distributed under the License is distributed on an "AS IS" BASIS,
-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-- See the License for the specific language governing permissions and
-- limitations under the License.
-----------------------------------------------------------------------
with Ada.Strings.Unbounded;
with Ada.Finalization;
with Ada.Calendar;
with Ada.Containers.Indefinite_Vectors;
with ADO.Utils;
with ADO.Dialects;
-- == Query Parameters ==
-- Query parameters are represented by the <tt>Parameter</tt> type which can represent almost
-- all database types including boolean, numbers, strings, dates and blob. Parameters are
-- put in a list represented by the <tt>Abstract_List</tt> or <tt>List</tt> types.
--
-- A parameter is added by using either the <tt>Bind_Param</tt> or the <tt>Add_Param</tt>
-- operation. The <tt>Bind_Param</tt> operation allows to specify either the parameter name
-- or its position. The <tt>Add_Param</tt> operation adds the parameter at end of the list
-- and uses the last position. In most cases, it is easier to bind a parameter with a name
-- as follows:
--
-- Query.Bind_Param ("name", "Joe");
--
-- and the SQL can use the following construct:
--
-- SELECT * FROM user WHERE name = :name
--
-- When the <tt>Add_Param</tt> is used, the parameter is not associated with any name but it
-- as a position index. Setting a parameter is easier:
--
-- Query.Add_Param ("Joe");
--
-- but the SQL cannot make any reference to names and must use the <tt>?</tt> construct:
--
-- SELECT * FROM user WHERE name = ?
--
-- === Parameter Expander ===
-- The parameter expander is a mechanism that allows to replace or inject values in the SQL
-- query by looking at an operation provided by the <tt>Expander</tt> interface. Such expander
-- is useful to replace parameters that are global to a session or to an application.
--
package ADO.Parameters is
use Ada.Strings.Unbounded;
type Token is new String;
type Parameter_Type is (T_NULL, T_STRING, T_TOKEN, T_LIST, T_DATE, T_LONG_INTEGER,
T_INTEGER, T_BOOLEAN, T_LONG_FLOAT, T_BLOB);
type Parameter (T : Parameter_Type;
Len : Natural;
Value_Len : Natural) is
record
Position : Natural := 0;
Name : String (1 .. Len);
case T is
when T_NULL =>
null;
when T_LONG_INTEGER =>
Long_Num : Long_Long_Integer := 0;
when T_INTEGER =>
Num : Integer;
when T_BOOLEAN =>
Bool : Boolean;
when T_LONG_FLOAT =>
Float : Long_Float;
when T_DATE =>
Time : Ada.Calendar.Time;
when T_BLOB =>
Data : ADO.Blob_Ref;
when others =>
Str : String (1 .. Value_Len);
end case;
end record;
type Expander is limited interface;
type Expander_Access is access all Expander'Class;
-- Expand the name from the given group into a target parameter value to be used in
-- the SQL query. The expander can look in a cache or in some configuration to find
-- the value associated with the name and return it. The Expander can return a
-- T_NULL when a value is not found or it may also raise some exception.
function Expand (Instance : in Expander;
Group : in String;
Name : in String) return Parameter is abstract;
type Abstract_List is abstract new Ada.Finalization.Controlled with private;
type Abstract_List_Access is access all Abstract_List'Class;
-- Set the SQL dialect description object.
procedure Set_Dialect (Params : in out Abstract_List;
D : in ADO.Dialects.Dialect_Access);
-- Set the cache expander to be used when expanding the SQL.
procedure Set_Expander (Params : in out Abstract_List;
Expander : in ADO.Parameters.Expander_Access);
-- Get the SQL dialect description object.
function Get_Dialect (From : in Abstract_List) return ADO.Dialects.Dialect_Access;
-- Add the parameter in the list.
procedure Add_Parameter (Params : in out Abstract_List;
Param : in Parameter) is abstract;
-- Set the parameters from another parameter list.
procedure Set_Parameters (Parameters : in out Abstract_List;
From : in Abstract_List'Class) is abstract;
-- Return the number of parameters in the list.
function Length (Params : in Abstract_List) return Natural is abstract;
-- Return the parameter at the given position
function Element (Params : in Abstract_List;
Position : in Natural) return Parameter is abstract;
-- Execute the <b>Process</b> procedure with the given parameter as argument.
procedure Query_Element (Params : in Abstract_List;
Position : in Natural;
Process : not null access
procedure (Element : in Parameter)) is abstract;
-- Clear the list of parameters.
procedure Clear (Parameters : in out Abstract_List) is abstract;
-- Operations to bind a parameter
procedure Bind_Param (Params : in out Abstract_List;
Name : in String;
Value : in Boolean);
procedure Bind_Param (Params : in out Abstract_List;
Name : in String;
Value : in Long_Long_Integer);
procedure Bind_Param (Params : in out Abstract_List;
Name : in String;
Value : in Identifier);
procedure Bind_Param (Params : in out Abstract_List;
Name : in String;
Value : in Integer);
procedure Bind_Param (Params : in out Abstract_List;
Name : in String;
Value : in ADO.Entity_Type);
procedure Bind_Param (Params : in out Abstract_List;
Name : in String;
Value : in String);
procedure Bind_Param (Params : in out Abstract_List;
Name : in String;
Value : in Unbounded_String);
procedure Bind_Param (Params : in out Abstract_List;
Name : in String;
Value : in Ada.Calendar.Time);
procedure Bind_Param (Params : in out Abstract_List;
Name : in String;
Value : in Token);
procedure Bind_Param (Params : in out Abstract_List;
Name : in String;
Value : in ADO.Blob_Ref);
procedure Bind_Param (Params : in out Abstract_List;
Name : in String;
Value : in ADO.Utils.Identifier_Vector);
procedure Bind_Param (Params : in out Abstract_List;
Position : in Natural;
Value : in Boolean);
procedure Bind_Param (Params : in out Abstract_List;
Position : in Natural;
Value : in Long_Long_Integer);
procedure Bind_Param (Params : in out Abstract_List;
Position : in Natural;
Value : in Long_Float);
procedure Bind_Param (Params : in out Abstract_List;
Position : in Natural;
Value : in Identifier);
procedure Bind_Param (Params : in out Abstract_List;
Position : in Natural;
Value : in Integer);
procedure Bind_Param (Params : in out Abstract_List;
Position : in Natural;
Value : in Entity_Type);
procedure Bind_Param (Params : in out Abstract_List;
Position : in Natural;
Value : in String);
procedure Bind_Param (Params : in out Abstract_List;
Position : in Natural;
Value : in Unbounded_String);
procedure Bind_Param (Params : in out Abstract_List;
Position : in Natural;
Value : in Ada.Calendar.Time);
procedure Bind_Param (Params : in out Abstract_List;
Position : in Natural;
Value : in ADO.Blob_Ref);
procedure Bind_Null_Param (Params : in out Abstract_List;
Position : in Natural);
procedure Bind_Null_Param (Params : in out Abstract_List;
Name : in String);
procedure Add_Param (Params : in out Abstract_List;
Value : in Boolean);
procedure Add_Param (Params : in out Abstract_List;
Value : in Long_Long_Integer);
procedure Add_Param (Params : in out Abstract_List;
Value : in Identifier);
procedure Add_Param (Params : in out Abstract_List;
Value : in Integer);
procedure Add_Param (Params : in out Abstract_List;
Value : in String);
procedure Add_Param (Params : in out Abstract_List;
Value : in Unbounded_String);
procedure Add_Param (Params : in out Abstract_List;
Value : in Ada.Calendar.Time);
-- Add a null parameter.
procedure Add_Null_Param (Params : in out Abstract_List);
-- Expand the SQL string with the query parameters. The following parameters syntax
-- are recognized and replaced:
-- <ul>
-- <li>? is replaced according to the current parameter index. The index is incremented
-- after each occurrence of ? character.
-- <li>:nnn is replaced by the parameter at index <b>nnn</b>.
-- <li>:name is replaced by the parameter with the name <b>name</b>
-- <li>$group[var-name] is replaced by using the expander interface.
-- </ul>
-- Parameter strings are escaped. When a parameter is not found, an empty string is used.
-- Returns the expanded SQL string.
function Expand (Params : in Abstract_List'Class;
SQL : in String) return String;
-- ------------------------------
-- List of parameters
-- ------------------------------
-- The <b>List</b> is an implementation of the parameter list.
type List is new Abstract_List with private;
overriding
procedure Add_Parameter (Params : in out List;
Param : in Parameter);
overriding
procedure Set_Parameters (Params : in out List;
From : in Abstract_List'Class);
-- Return the number of parameters in the list.
overriding
function Length (Params : in List) return Natural;
-- Return the parameter at the given position
overriding
function Element (Params : in List;
Position : in Natural) return Parameter;
-- Execute the <b>Process</b> procedure with the given parameter as argument.
overriding
procedure Query_Element (Params : in List;
Position : in Natural;
Process : not null access procedure (Element : in Parameter));
-- Clear the list of parameters.
overriding
procedure Clear (Params : in out List);
private
function Compare_On_Name (Left, Right : in Parameter) return Boolean;
package Parameter_Vectors is
new Ada.Containers.Indefinite_Vectors (Index_Type => Positive,
Element_Type => Parameter,
"=" => Compare_On_Name);
type Abstract_List is abstract new Ada.Finalization.Controlled with record
Dialect : ADO.Dialects.Dialect_Access := null;
Expander : Expander_Access;
end record;
type List is new Abstract_List with record
Params : Parameter_Vectors.Vector;
end record;
end ADO.Parameters;
|