Last modified by christoph_lechleitner@iteg_at on 2013-01-31 07.32:56

From version 7.1
edited by christoph_lechleitner@iteg_at
on 2013-01-31 07.32:55
Change comment: There is no comment for this version
To version 2.1
edited by 5fbc055b7cc103006957e1ae
on 2012-06-14 06.29:38
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1 -XWiki.christoph_lechleitner@iteg_at
1 +XWiki.5fbc055b7cc103006957e1ae
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1 1  = {{id name="HowTocreateandupdateDatabasesusingSchemaManagerandSchemaUpdateSnippets-Preliminary"/}}Preliminary =
2 2  
3 -The SchemaManager ({{code language="none"}}org.clazzes.jdbc2xml.schema.SchemaManager{{/code}}) and SchemaEngine provide means to maintain the database scheme of an application, allowing you to add and delete tables, columns, relations and data in the database along application updates.
3 +The SchemaManager and SchemaEngine give you an abstracted access to the database schema of your application, allowing you to add and delete tables, columns, relations and data in the database on application updates. It uses a designated table to keep track of the current schema status, which it will check whenever it is run, and update the database if it is not at the correct version.
4 4  
5 -=== {{id name="HowTocreateandupdateDatabasesusingSchemaManagerandSchemaUpdateSnippets-SchemaHistoryTable"/}}Schema History Table ===
5 +SchemaManager ({{code language="none"}}org.clazzes.jdbc2xml.schema.SchemaManager{{/code}}) will create a table called SCHEMA_HISTORY if it can not find it the first time it is run. This table contains the following columns:
6 6  
7 -A designated schema table, by default named SCHEMA_HISTORY, is used to keep track of the current scheme. It will be automatically at SchemaManager's first run. (% style="font-size: 10.0pt;line-height: 13.0pt;" %)SCHEMA_HISTORY contains the following columns:
7 +{{code language="none"}}
8 +VERSION:varchar(10), not null, primary key
9 +DESCRIPTION:varchar(512), nullable
10 +CREATION_DATE:date, nullable
11 +SERIALNR:integer(5), not null
12 +{{/code}}
8 8  
9 -|=(((
10 -
11 -)))|=(((
12 -
13 -)))
14 -|(((
15 -(% class="code" %)
16 -(((
17 -VERSION
18 -)))
19 -)))|(((
20 -(% class="code" %)
21 -(((
22 -varchar(10), not null, primary key
23 -)))
24 -)))
25 -|(((
26 -(% class="code" %)
27 -(((
28 -DESCRIPTION
29 -)))
30 -)))|(((
31 -(% class="code" %)
32 -(((
33 -varchar(512), nullable
34 -)))
35 -)))
36 -|(((
37 -(% class="code" %)
38 -(((
39 -CREATION_DATE
40 -)))
41 -)))|(((
42 -(% class="code" %)
43 -(((
44 -date, nullable
45 -)))
46 -)))
47 -|(((
48 -(% class="code" %)
49 -(((
50 -SERIALNR
51 -)))
52 -)))|(((
53 -(% class="code" %)
54 -(((
55 -integer(5), not null
56 -)))
57 -)))
58 -
59 -=== {{id name="HowTocreateandupdateDatabasesusingSchemaManagerandSchemaUpdateSnippets-CustomnameforSchemaHistoryTable"/}}Custom name for Schema History Table ===
60 -
61 -(% style="font-size: 10.0pt;line-height: 13.0pt;" %)In (% style="font-size: 10.0pt;font-weight: normal;line-height: 13.0pt;" %)heterogenous environments as well as in heavily modularized software architectures a single database may be shared by multiple parties each requiring a couple of tables.
62 -
63 -(% style="font-size: 10.0pt;font-weight: normal;line-height: 13.0pt;" %)To allow multiple modules (applications, libraries, other OSGi bundles) to use (% style="font-size: 10.0pt;line-height: 13.0pt;" %)JDBC2XML's SchemaManager concurrently within one database, as of JDBC 1.1.1 SchemaManager hold the name of the schema history table in an overwritable property, {{code language="none"}}versionHistoryTable{{/code}}. See (%%)[[JDBCTOXML-11>>url:https://jira.clazzes.org/browse/JDBCTOXML-11||shape="rect"]](% style="font-size: 10.0pt;line-height: 13.0pt;" %).
64 -
65 65  = {{id name="HowTocreateandupdateDatabasesusingSchemaManagerandSchemaUpdateSnippets-ProjectConfiguration"/}}Project Configuration =
66 66  
67 -SchemaManager requires a DataSource ({{code language="none"}}javax.sql.DataSource{{/code}}) and a list of TableInfo ({{code language="none"}}org.clazzes.jdbc2xml.schema.TableInfo{{/code}}) Objects, from which database structures will be created if an "empty" database is detected. Furthermore, an implementation of ISchemaEngine ({{code language="none"}}org.clazzes.jdbc2xml.schema.ISchemaEngine{{/code}}) is required.
16 +To function correctly, SchemaManager needs a DataSource ({{code language="none"}}javax.sql.DataSource{{/code}}) and a list of TableInfo ({{code language="none"}}org.clazzes.jdbc2xml.schema.TableInfo{{/code}}) Objects, from which a database will be created if it finds an empty database. To function properly, it also needs an implementation of ISchemaEngine ({{code language="none"}}org.clazzes.jdbc2xml.schema.ISchemaEngine{{/code}}).
68 68  
69 -Optionally, a base version (default value 0.1.00) and a base description String (default "initial database schema") may be specified.
18 +Optionally, you may set the base version (default value 0.1.00) and base description String (default "initial database schema").
70 70  
71 71  Database updates are passed as a Map<String, ISchemaUpdateSnippet> (org.clazzes.jdbc2xml.schema.ISchemaUpdateSnippet) - details see below.
72 72  
73 73  To perform the operations, call {{code language="none"}}SchemaManager.start(){{/code}}.
74 74  
75 -=== {{id name="HowTocreateandupdateDatabasesusingSchemaManagerandSchemaUpdateSnippets-ConfigurationusingSpringorOSGi/Blueprint"/}}Configuration using Spring or OSGi/Blueprint ===
24 +=== {{id name="HowTocreateandupdateDatabasesusingSchemaManagerandSchemaUpdateSnippets-UsingSpringorOSGi/Blueprint"/}}Using Spring or OSGi/Blueprint ===
76 76  
77 77  If you are using OSGi with Blueprint or Spring to set up your project, you can configure a SchemaManager instance by adding the following to your blueprint {{code language="none"}}services.xml{{/code}} (or Spring configuration file):
78 78  
... ... @@ -84,7 +84,7 @@
84 84  </bp:reference>
85 85   
86 86  <bp:bean id="sqlDialect" factory-ref="dialectFactory" factory-method="newDialect">
87 -<bp:argument ref="jdbcUrl"><!-- bean jdbcUrl specified above -->
36 +<bp:argument> <!-- Pass JDBC URL as an argument -->
88 88  </bp:argument>
89 89  </bp:bean>
90 90   
... ... @@ -92,46 +92,28 @@
92 92  <bp:property name="dialect" ref="sqlDialect">
93 93  </bp:property>
94 94  </bp:bean>
95 -
96 96   
97 -<bp:bean id="initialSchema" class="foo.schema.InitialSchema"></bp:bean>
98
99 99  <bp:bean id="databaseSetup" class="org.clazzes.jdbc2xml.schema.SchemaManager" init-method="start">
100 100  <bp:property name="dataSource" ref="dataSource"></bp:property>
101 101  <bp:property name="schemaEngine" ref="schemaEngine"></bp:property>
102 - <!-- optional but recommended: special name for schema history table: -->
103 - <bp:property name="versionHistoryTable" value="MYLIB_SCHEMA_HISTORY"/>
104 - <!-- optional but recommended: explicit first version -->
105 105  <bp:property name="baseVersion" value="0.1.00" />
106 106  <bp:property name="baseTables">
107 -<!-- List of TableDefinitions here (see below), typical: -->
108 - <bp:bean factory-ref="initialSchema" factory-method="getSchema" />
50 +<!-- Add List of TableDefinitions here -->
109 109  </bp:property>
110 - <!-- Add Update-Snippets here, example for updates from 0.1.00 to 0.1.01 and on to 0.2.00
111 111  <bp:property name="upateSnippets">
112 -<bp:map>
113 - <bp:entry key="0.1.00" value="foo.schema.SchemaUpdate_0_1_01"></bp:entry>
114 - <bp:entry key="0.1.01" value="foo.schema.SchemaUpdate_0_2_00"></bp:entry>
115 -</bp:map>
53 +<!-- Add Update-Snippets here -->
116 116  </bp:property>
117 - -->
118 118  </bp:bean>
119 119  {{/code}}
120 120  
121 -By default, JDBC2XML provides an implementation of IDialectFactory and ISchemaEngineFactory as an OSGi service or via ServiceRegistry for Spring.
58 +By default, JDBC2XML provides an implementation of IDialectFactory and ISchemaEngineFactory as an OSGi service or via ServiceRegistry lookup for Spring.
122 122  
123 123  = {{id name="HowTocreateandupdateDatabasesusingSchemaManagerandSchemaUpdateSnippets-Settingupaninitialdatabaseschema"/}}Setting up an initial database schema =
124 124  
125 -=== {{id name="HowTocreateandupdateDatabasesusingSchemaManagerandSchemaUpdateSnippets-InitalSchema(InitialTableList)"/}}Inital Schema (Initial Table List) ===
62 +To create an initial database schema, you will need to provide SchemaManager with a list of TableInfo objects. The recommended way to do this is to provide a class in your project which creates this list in it's constructor and provides it through a getter. You can instantiate this class in your Spring/Blueprint config as a singleton, and feed the provided List to SchemaManager. An example of this class could look like this:
126 126  
127 -To create an initial database schema, SchemaManager needs a list of TableInfo objects.
128 -
129 -The recommended strategy is to create an InitialSchema class providing this list through a getter.
130 -
131 -(% style="font-size: 10.0pt;line-height: 13.0pt;" %)This is an example:
132 -
133 133  {{code language="java"}}
134 -package foo.schema;
65 +package org.clazzes.example.jdbc2xml;
135 135  
136 136  import java.sql.Types;
137 137  import java.util.Arrays;
... ... @@ -142,225 +142,81 @@
142 142  import org.clazzes.jdbc2xml.schema.PrimaryKeyInfo;
143 143  import org.clazzes.jdbc2xml.schema.TableInfo;
144 144   
145 -public class InitialSchema {
76 +public class TableDefinitions {
146 146  
78 + /* It is adviseable to provide the Strings used as names for tables and columns as
79 + constants, so they can be reused to build sql-statements */
80 + public static final String TB_EXAMPLE_TABLE_NAME = "ADDRESSBOOK";
81 + public static final String COL_EXAMPLE_ID = "ID";
82 + public static final String COL_EXAMPLE_NAME = "NAME";
83 + public static final String COL_EXAMPLE_ADDRESS_REF = "ADDRESS";
84 + public static final String COL_EXAMPLE_BIRTHDAY = "BIRTHDAY";
85
86 + /* ... */
87
147 147   private List<TableInfo> setup;
148 148  
149 - public InitialSchema() {
150 -// Create a table
151 -TableInfo exampleTable = new TableInfo(TableDefs.TABLENAME_ADDRESSBOOK);
90 + public TableDefinitions() {
91 +/* Create a table */
92 +TableInfo exampleTable = new TableInfo(TB_EXAMPLE_TABLE_NAME);
152 152  exampleTable.setColumns(
153 153   Arrays.asList(new ColumnInfo[] {
154 -new ColumnInfo(TableDefs.COL_ADDRESSBOOK_ID, Types.BIGINT, 20, null, false, null,true),
155 -new ColumnInfo(TableDefs.COL_ADDRESSBOOK_NAME, Types.VARCHAR, 256, null, false, null),
156 -new ColumnInfo(TableDefs.COL_ADDRESSBOOK_ADDRESS_REF, Types.BIGINT, 20, null, true, null),
157 -new ColumnInfo(TableDefs.COL_ADDRESSBOOK_BIRTHDAY, Types.DATE, 12, null, false, null)
95 +new ColumnInfo(COL_EXAMPLE_ID, Types.BIGINT, 20, null, false, null,true),
96 +new ColumnInfo(COL_EXAMPLE_NAME, Types.VARCHAR, 256, null, false, null),
97 +new ColumnInfo(COL_EXAMPLE_ADDRESS_REF, Types.BIGINT, 20, null, true, null),
98 +new ColumnInfo(COL_EXAMPLE_BIRTHDAY, Types.DATE, 12, null, false, null)
158 158  }));
159 159   
160 -// Example for creating a primary key
101 +/* Example for creating a foreign key reference */
102 +exampleTable.setForeignKeys(Arrays.asList(new ForeignKeyInfo[] {
103 +new ForeignKeyInfo("FK_EXAMPLE_ADDRESS", COL_EXAMPLE_ADDRESS_REF, TB_ADDRESS, COL_ADDRESS_ID)
104 +}));
105
106 +/* Example for creating a primary key */
161 161  exampleTable.setPrimaryKey(
162 -new PrimaryKeyInfo("PK_EXAMPLE", COL_ADDRESSBOOK_ID)
108 +new PrimaryKeyInfo("PK_EXAMPLE", COL_EXAMPLE_ID)
163 163  );
164 164  
165 -// Example for creating a foreign key reference
166 -exampleTable.setForeignKeys(Arrays.asList(new ForeignKeyInfo[] {
167 -new ForeignKeyInfo("FK_EXAMPLE_ADDRESS", TableDefs.COL_ADDRESSBOOK_ADDRESS_REF, TableDefs.TABLENAME_ADDRESSES, TableDefs.COL_ADDRESS_ID)
168 -}));
111 +/* ... */
169 169   
170 -// ...
171
172 172  this.setup = Arrays.asList(
173 173  exampleTable,
174 -// ...
115 +/* ... */
175 175  );
176 176  
177 177   }
178 178    
179 - public List<TableInfo> getSchema() {
180 -return this.schema;
120 + public List<TableInfo> getSetup() {
121 +return this.setup;
181 181   }
182 182  
183 183  }
184 184  {{/code}}
185 185  
186 -=== {{id name="HowTocreateandupdateDatabasesusingSchemaManagerandSchemaUpdateSnippets-TableDefs,acentralplacefortableandcolumnnames"/}}TableDefs, a central place for table and column names ===
127 +You must inject {{code language="none"}}TableDefinitions.getSetup(){{/code}} into {{code language="none"}}SchemaManager.setBaseTables(){{/code}} before calling {{code language="none"}}SchemaManager.start(){{/code}}.
187 187  
188 -You may have notice the usage of {{code language="none"}}TableDefs.*{{/code}} members.
129 +Using Blueprint/Spring, you can do this with the following snippet:
189 189  
190 -Table and column names should never be re-typed everywhere as literals, it is highly recommended to use constants.
191 -
192 -Putting these constants in a dedicated class, say {{code language="none"}}TableDef{{/code}}, allows to use this as an easily accessible list of all tables and columns in the database.
193 -
194 -This is an example:
195 -
196 -{{code language="java"}}
197 -package foo.schema;
198 -
199 -public class TableDefs {
200 -
201 - // It is adviseable to provide the Strings used as names for tables and columns as constants,
202 - // so they can be reused savely to construct SQL statements
131 +{{code language="none"}}
203 203   
204 - // 0.1.00
205 - public static final String TABLENAME_ADDRESSBOOK = "ADDRESSBOOK";
206 - public static final String COL_ADDRESSBOOK_ID = "ID";
207 - public static final String COL_ADDRESSBOOK_NAME = "NAME";
208 - public static final String COL_ADDRESSBOOK_ADDRESS_REF = "ADDRESS";
209 - public static final String COL_ADDRESSBOOK_BIRTHDAY = "BIRTHDAY";
210 - // 0.1.01
211 -public static final String COL_ADDRESSBOOK_GENDER = "GENDER";
212
213 -}
214 214  {{/code}}
215 215  
216 -=== {{id name="HowTocreateandupdateDatabasesusingSchemaManagerandSchemaUpdateSnippets-Triggeringthecreationoftheinitialschema"/}}Triggering the creation of the initial schema ===
135 += {{id name="HowTocreateandupdateDatabasesusingSchemaManagerandSchemaUpdateSnippets-UpdatingadatabaseschemawithSchemaUpdateSnippets"/}}Updating a database schema with SchemaUpdateSnippets =
217 217  
218 -(% style="font-size: 10.0pt;line-height: 13.0pt;" %)To trigger the creation of the initial schema when coming across an empty database, (% style="font-size: 10.0pt;line-height: 13.0pt;" %){{code language="none"}}InitialSchema.getSchema(){{/code}} has to be injected into (% style="font-size: 10.0pt;line-height: 13.0pt;" %){{code language="none"}}SchemaManager.setBaseTables(){{/code}} before calling (% style="font-size: 10.0pt;line-height: 13.0pt;" %){{code language="none"}}SchemaManager.start(){{/code}}.
219 -
220 -Using Blueprint/Spring, you can do this by inserting the following snippet in the bean definition for SchemaManager:
221 -
222 -{{code language="html/xml"}}
223 -<bp:bean id="initialSchema" class="foo.schema.InitialSchema"></bp:bean>
224
225 -<bp:property name="baseTables">
226 -<bp:bean factory-ref="initialSchema" factory-method="getSchema" />
227 -</bp:property>
228 -
229 -{{/code}}
230 -
231 -= {{id name="HowTocreateandupdateDatabasesusingSchemaManagerandSchemaUpdateSnippets-UpdatingadatabaseschemawithISchemaUpdateSnippet"/}}Updating a database schema with ISchemaUpdateSnippet =
232 -
233 233  To update the database or it's content with schema updates, you must create a new implementation of ISchemaUpdateSnippet ({{code language="none"}}org.clazzes.jdbc2xml.schema.ISchemaUpdateSnippet{{/code}}) for each consecutive update. SchemaManager takes a {{code language="none"}}Map<String, Class<? extends ISchemaUpdateSnippet>>{{/code}} which contains the update classes keyed by the originating (e.g. previous) version.
234 234  
235 -An example for an implementation of a schema update snippet could look like this:
139 +
236 236  
237 -{{code language="java"}}
238 -package foo.schema;
141 +
239 239  
240 -import java.sql.SQLException;
241 -import java.sql.Types;
242 -import java.util.Arrays;
243 -import org.clazzes.jdbc2xml.schema.ColumnInfo;
244 -import org.clazzes.jdbc2xml.schema.ISchemaEngine;
245 -import org.clazzes.jdbc2xml.schema.ISchemaUpdateSnippet;
246 -import org.clazzes.jdbc2xml.schema.PrimaryKeyInfo;
247 -import org.clazzes.jdbc2xml.schema.TableInfo;
143 +
248 248  
249 -public class SchemaUpdate_0_1_01 implements ISchemaUpdateSnippet {
250
251 -// This is only accessed through the getter
252 -private static final String TARGET_VERSION = "0.1.01";
253
254 -@Override
255 -public String getTargetVersion() {
256 -return TARGET_VERSION;
257 -}
145 +
258 258  
259 -@Override
260 -public String getUpdateComment() {
261 -return "Adding column "+TableDefs.COL_ADDRESSBOOK_GENDER+" to table "+TableDefs.TABLENAME_ADDRESSBOOK+".";
262 -}
147 +
263 263  
264 -@Override
265 -public void performUpdate(ISchemaEngine schemaEngine) throws SQLException {
266 -TableInfo ti = schemaEngine.fetchTableInfo(TableDefs.TABLENAME_ADDRESSBOOK, null);
267 -schemaEngine.addColumn(ti, new ColumnInfo(TableDefs.COL_ADDRESSBOOK_GENDER, Types.VARCHAR, 1, null, true, null));
268 -}
269 -}
149 +
270 270  
151 +
271 271  
272 -{{/code}}
273 -
274 -The return values of {{code language="none"}}ISchemaUpdateSnippet.getTargetVersion(){{/code}} and {{code language="none"}}ISchemaUpdateSnippet.getUpdateComment(){{/code}} are written to the {{code language="none"}}SCHEMA_HISTORY{{/code}} table. The update itself is performed in {{code language="none"}}ISchemaUpdateSnippet.performUpdate(){{/code}}. In the above example, it adds a column called {{code language="none"}}GENDER{{/code}} to the ADDRESSBOOK table created via the InitialSchema class above.
275 -
276 -To add an entire table you would use the {{code language="none"}}ISchemaEngine.createTable(){{/code}} method, like this:
277 -
278 -{{code language="java"}}
279 -@Override
280 -public void performUpdate(ISchemaEngine schemaEngine) throws SQLException {
281 - TableInfo tiGroup = new TableInfo(TB_GROUP);
282 - tiGroup.setColumns(Arrays.asList(new ColumnInfo[] {
283 - new ColumnInfo(TableDefs.COL_ID, Types.VARCHAR, 36, null, false, null),
284 - new ColumnInfo(TableDefs.COL_NAME, Types.VARCHAR, 100, null, false, null),
285 - new ColumnInfo(TableDefs.COL_DESCRIPTION, Types.VARCHAR, 512, null, true, null)
286 - }));
287 - tiGroup.setPrimaryKey(new PrimaryKeyInfo(PK_GROUP, TableDefs.COL_ID));
288 - tiGroup.setIndices(Arrays.asList(new IndexInfo(IDX_GROUP_01, TableDefs.COL_NAME, true, null)));
289 -
290 -schemaEngine.createTable(tiGroup, true);
291 -}
292 -{{/code}}
293 -
294 -Executing a PreparedStatement also works, using ISchemaEngine.getConnection() to retrieve the database connection:
295 -
296 -{{code language="java"}}
297 -@Override
298 -public void performUpdate(ISchemaEngine schemaEngine) throws SQLException {
299 - String sql = "UPDATE "+TableDefs.TB_EXAMPLE_TABLE_NAME+" SET "+TableDefs.COL_EXAMPLE_NAME+"=?";
300 -
301 - PreparedStatement ps = schemaEngine.getConnection().prepareStatement(sql);
302 -
303 - ps.setNull(1, Types.VARCHAR);
304 -
305 - ps.execute();
306 -}
307 -{{/code}}
308 -
309 -To create the map of updates in Blueprint/Spring and inject them into SchemaManager, use the following xml-Snippet:
310 -
311 -{{code language="html/xml"}}
312 -<!-- SchemaManager bean definition starts here ... -->
313 -<bp:property name="upateSnippets">
314 -<bp:map>
315 -<bp:entry key="0.1.00" value="org.clazzes.example.jdbc2xml.updates.SchemaUpdate0_1_01"></bp:entry>
316 -<!-- more entries come here: "key" is the schema version to update, "value" the qualified classname of the schema update -->
317 -</bp:map>
318 -</bp:property>
319 -<!-- ... and continues here -->
320 -{{/code}}
321 -
322 -= {{id name="HowTocreateandupdateDatabasesusingSchemaManagerandSchemaUpdateSnippets-SchemaMaintainanceStrategies"/}}Schema Maintainance Strategies =
323 -
324 -The JDBC2XML Schema management tools allow for 2 different strategies:
325 -
326 -=== {{id name="HowTocreateandupdateDatabasesusingSchemaManagerandSchemaUpdateSnippets-Frozen(Initial)TableList"/}}Frozen (% style="font-size: 14.0pt;" %)(Initial) Table List(%%) ===
327 -
328 -The legacy strategy is:
329 -
330 -(% style="list-style-type: square;" %)
331 -* At the start of a project, create and use {{code language="none"}}InitalSchema.java{{/code}}
332 -* After the first commit, {{code language="none"}}InitalSchema{{/code}} are considered frozen, all changes go into {{code language="none"}}SchemaUpdates{{/code}}, up to one update per source code commit
333 -
334 -Advantage: Rock solid.
335 -
336 -Disadvantage: No place to look for the complete and exact current scheme, except actual databases. {{code language="none"}}TableDefs.java{{/code}} provide some information, but may become confusing in the long term.
337 -
338 -=== {{id name="HowTocreateandupdateDatabasesusingSchemaManagerandSchemaUpdateSnippets-Possiblebutdangerous:Evolving(Initial)TableList"/}}Possible but dangerous: Evolving (Initial) Table List ===
339 -
340 -To keep the (Initial) Schema up do date, one might use this strategy:
341 -
342 -(% style="list-style-type: square;" %)
343 -* keep the {{code language="none"}}InitalSchema{{/code}} up to date, so an empty database always gets the current scheme in one shot
344 -* {{code language="none"}}SchemaUpdates{{/code}} are only applied to existing databases
345 -
346 -Advantage: Immediate overview over exact current scheme.
347 -
348 -Disadvantage: Very real danger of messing something up, because
349 -
350 -(% style="list-style-type: square;" %)
351 -* schema updates have to be coded in 2 different places in 2 different ways
352 -* the bean definition has to be maintained in 2 places but just 1
353 -
354 -Conclusion: **DO NOT DO THIS**. This strategy may be ok in very early stages, but at some point it has to be
355 -
356 -=== {{id name="HowTocreateandupdateDatabasesusingSchemaManagerandSchemaUpdateSnippets-Recommendation:FreezeInitialTableDefinitionnotlaterthanthefirstReleaseCandidate(RC)"/}}(% style="font-size: 14.0pt;" %)Recommendation: Freeze Initial Table Definition not later than the first Release Candidate (RC)(%%) ===
357 -
358 -It may be ok to start a new project using a fast changing (% style="font-size: 10.0pt;line-height: 13.0pt;" %)(Initial) Table List.
359 -
360 -(% style="font-size: 10.0pt;line-height: 13.0pt;" %)But, please, freeze it at some point. Once the first test server is setup up, internally or at a friendly customer, the Frozen Initial Table List Strategy is the only valid one!
361 -
362 -= {{id name="HowTocreateandupdateDatabasesusingSchemaManagerandSchemaUpdateSnippets-RealworldExample"/}}Real world Example =
363 -
364 -This HowTo is currently evolving while an additional developer gets acostumed to the SchemaEngine, for developing [[SDS' org.clazzes.sds.impl.schema package>>url:http://svn.clazzes.org/svn/sds/trunk/sds.impl/src/main/java/org/clazzes/sds/impl/schema||style="font-size: 10.0pt;line-height: 13.0pt;" shape="rect"]](% style="font-size: 10.0pt;line-height: 13.0pt;" %) which is **work in progress**!
365 -
366 -(% style="font-size: 10.0pt;line-height: 13.0pt;" %)\\
153 +
Confluence.Code.ConfluencePageClass[0]
Id
... ... @@ -1,1 +1,1 @@
1 -656798
1 +656809
URL
... ... @@ -1,1 +1,1 @@
1 -https://clazzes.atlassian.net/wiki/spaces/JDBC2XML/pages/656798/How To create and update Databases using SchemaManager and SchemaUpdateSnippets
1 +https://clazzes.atlassian.net/wiki/spaces/JDBC2XML/pages/656809/How To create and update Databases using SchemaManager and SchemaUpdateSnippets