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Last modified by christoph_lechleitner@iteg_at on 2013-01-31 07.32:56
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edited by christoph_lechleitner@iteg_at
on 2013-01-31 07.32:56
Change comment: Migrated to Confluence 5.3
To version 6.1
edited by christoph_lechleitner@iteg_at
on 2013-01-31 07.04:57
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... ... @@ -92,10 +92,7 @@
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>
... ... @@ -105,7 +105,7 @@
105 105  <bp:property name="baseVersion" value="0.1.00" />
106 106  <bp:property name="baseTables">
107 107  <!-- List of TableDefinitions here (see below), typical: -->
108 - <bp:bean factory-ref="initialSchema" factory-method="getSchema" />
105 + <!-- <bp:bean factory-ref="tableDefinitions" factory-method="getSetup" /> -->
109 109  </bp:property>
110 110   <!-- 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">
... ... @@ -122,8 +122,6 @@
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) ===
126 -
127 127  To create an initial database schema, SchemaManager needs a list of TableInfo objects.
128 128  
129 129  The recommended strategy is to create an InitialSchema class providing this list through a getter.
... ... @@ -131,7 +131,7 @@
131 131  (% style="font-size: 10.0pt;line-height: 13.0pt;" %)This is an example:
132 132  
133 133  {{code language="java"}}
134 -package foo.schema;
129 +package org.clazzes.example.jdbc2xml;
135 135  
136 136  import java.sql.Types;
137 137  import java.util.Arrays;
... ... @@ -146,27 +146,27 @@
146 146  
147 147   private List<TableInfo> setup;
148 148  
149 - public InitialSchema() {
144 + public TableDefinitions() {
150 150  // Create a table
151 -TableInfo exampleTable = new TableInfo(TableDefs.TABLENAME_ADDRESSBOOK);
146 +TableInfo exampleTable = new TableInfo(TableDefs.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)
149 +new ColumnInfo(TableDefs.COL_EXAMPLE_ID, Types.BIGINT, 20, null, false, null,true),
150 +new ColumnInfo(TableDefs.COL_EXAMPLE_NAME, Types.VARCHAR, 256, null, false, null),
151 +new ColumnInfo(TableDefs.COL_EXAMPLE_ADDRESS_REF, Types.BIGINT, 20, null, true, null),
152 +new ColumnInfo(TableDefs.COL_EXAMPLE_BIRTHDAY, Types.DATE, 12, null, false, null)
158 158  }));
159 159   
160 -// Example for creating a primary key
161 -exampleTable.setPrimaryKey(
162 -new PrimaryKeyInfo("PK_EXAMPLE", COL_ADDRESSBOOK_ID)
163 -);
164 -
165 165  // Example for creating a foreign key reference
166 166  exampleTable.setForeignKeys(Arrays.asList(new ForeignKeyInfo[] {
167 -new ForeignKeyInfo("FK_EXAMPLE_ADDRESS", TableDefs.COL_ADDRESSBOOK_ADDRESS_REF, TableDefs.TABLENAME_ADDRESSES, TableDefs.COL_ADDRESS_ID)
157 +new ForeignKeyInfo("FK_EXAMPLE_ADDRESS", COL_EXAMPLE_ADDRESS_REF, TB_ADDRESS, COL_ADDRESS_ID)
168 168  }));
169 169   
160 +// Example for creating a primary key
161 +exampleTable.setPrimaryKey(
162 +new PrimaryKeyInfo("PK_EXAMPLE", COL_EXAMPLE_ID)
163 +);
164 +
170 170  // ...
171 171   
172 172  this.setup = Arrays.asList(
... ... @@ -183,49 +183,45 @@
183 183  }
184 184  {{/code}}
185 185  
186 -=== {{id name="HowTocreateandupdateDatabasesusingSchemaManagerandSchemaUpdateSnippets-TableDefs,acentralplacefortableandcolumnnames"/}}TableDefs, a central place for table and column names ===
181 +{{code language="java"}}
182 +package org.clazzes.example.jdbc2xml;
187 187  
188 -You may have notice the usage of {{code language="none"}}TableDefs.*{{/code}} members.
184 +import java.sql.Types;
185 +import java.util.Arrays;
186 +import java.util.List;
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;
188 +import org.clazzes.jdbc2xml.schema.ColumnInfo;
189 +import org.clazzes.jdbc2xml.schema.ForeignKeyInfo;
190 +import org.clazzes.jdbc2xml.schema.PrimaryKeyInfo;
191 +import org.clazzes.jdbc2xml.schema.TableInfo;
198 198  
199 199  public class TableDefs {
200 200  
201 201   // It is adviseable to provide the Strings used as names for tables and columns as constants,
202 202   // so they can be reused savely to construct SQL statements
203 - 
204 - // 0.1.00
205 205   public static final String TABLENAME_ADDRESSBOOK = "ADDRESSBOOK";
206 206   public static final String COL_ADDRESSBOOK_ID = "ID";
207 207   public static final String COL_ADDRESSBOOK_NAME = "NAME";
208 208   public static final String COL_ADDRESSBOOK_ADDRESS_REF = "ADDRESS";
209 209   public static final String COL_ADDRESSBOOK_BIRTHDAY = "BIRTHDAY";
210 - // 0.1.01
211 -public static final String COL_ADDRESSBOOK_GENDER = "GENDER";
212 - 
202 +
213 213  }
214 214  {{/code}}
215 215  
216 -=== {{id name="HowTocreateandupdateDatabasesusingSchemaManagerandSchemaUpdateSnippets-Triggeringthecreationoftheinitialschema"/}}Triggering the creation of the initial schema ===
206 +
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}}.
208 +
219 219  
210 +You must inject {{code language="none"}}TableDefinitions.getSetup(){{/code}} into {{code language="none"}}SchemaManager.setBaseTables(){{/code}} before calling {{code language="none"}}SchemaManager.start(){{/code}}.
211 +
220 220  Using Blueprint/Spring, you can do this by inserting the following snippet in the bean definition for SchemaManager:
221 221  
222 222  {{code language="html/xml"}}
223 -<bp:bean id="initialSchema" class="foo.schema.InitialSchema"></bp:bean>
224 - 
215 +<!-- SchemaManager bean definition starts here ... -->
225 225  <bp:property name="baseTables">
226 -<bp:bean factory-ref="initialSchema" factory-method="getSchema" />
217 +<bp:bean factory-ref="tableDefinitions" factory-method="getSetup" />
227 227  </bp:property>
228 -
219 +<!-- ... and continues here -->
229 229  {{/code}}
230 230  
231 231  = {{id name="HowTocreateandupdateDatabasesusingSchemaManagerandSchemaUpdateSnippets-UpdatingadatabaseschemawithISchemaUpdateSnippet"/}}Updating a database schema with ISchemaUpdateSnippet =
... ... @@ -235,7 +235,7 @@
235 235  An example for an implementation of a schema update snippet could look like this:
236 236  
237 237  {{code language="java"}}
238 -package foo.schema;
229 +package org.clazzes.example.jdbc2xml.updates;
239 239  
240 240  import java.sql.SQLException;
241 241  import java.sql.Types;
... ... @@ -246,11 +246,15 @@
246 246  import org.clazzes.jdbc2xml.schema.PrimaryKeyInfo;
247 247  import org.clazzes.jdbc2xml.schema.TableInfo;
248 248  
249 -public class SchemaUpdate_0_1_01 implements ISchemaUpdateSnippet {
240 +public class SchemaUpdate0_1_01 implements ISchemaUpdateSnippet {
250 250   
251 251  // This is only accessed through the getter
252 252  private static final String TARGET_VERSION = "0.1.01";
253 253   
245 +// Here it is also adviseable to define constants for reuse in statements.
246 +public static final String COL_EXAMPLE_GENDER = "GENDER";
247 +
248 +
254 254  @Override
255 255  public String getTargetVersion() {
256 256  return TARGET_VERSION;
... ... @@ -258,13 +258,13 @@
258 258  
259 259  @Override
260 260  public String getUpdateComment() {
261 -return "Adding column "+TableDefs.COL_ADDRESSBOOK_GENDER+" to table "+TableDefs.TABLENAME_ADDRESSBOOK+".";
256 +return "Adding column "+COL_EXAMPLE_GENDER+" to table "+TableDefinitions.TB_EXAMPLE_TABLE_NAME+".";
262 262  }
263 263  
264 264  @Override
265 265  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));
261 +TableInfo ti = schemaEngine.fetchTableInfo(TableDefinitions.TB_EXAMPLE_TABLE_NAME, null);
262 + schemaEngine.addColumn(ti, new ColumnInfo(COL_EXAMPLE_GENDER, Types.VARCHAR, 1, null, true, null));
268 268  }
269 269  }
270 270  
... ... @@ -271,7 +271,7 @@
271 271  
272 272  {{/code}}
273 273  
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.
269 +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 example table created by the TableDefinitions class above.
275 275  
276 276  To add an entire table you would use the {{code language="none"}}ISchemaEngine.createTable(){{/code}} method, like this:
277 277  
... ... @@ -280,12 +280,12 @@
280 280  public void performUpdate(ISchemaEngine schemaEngine) throws SQLException {
281 281   TableInfo tiGroup = new TableInfo(TB_GROUP);
282 282   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)
278 + new ColumnInfo(TableDefinitions.COL_ID, Types.VARCHAR, 36, null, false, null),
279 + new ColumnInfo(TableDefinitions.COL_NAME, Types.VARCHAR, 100, null, false, null),
280 + new ColumnInfo(TableDefinitions.COL_DESCRIPTION, Types.VARCHAR, 512, null, true, null)
286 286   }));
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)));
282 + tiGroup.setPrimaryKey(new PrimaryKeyInfo(PK_GROUP, TableDefinitions.COL_ID));
283 + tiGroup.setIndices(Arrays.asList(new IndexInfo(IDX_GROUP_01, TableDefinitions.COL_NAME, true, null)));
289 289  
290 290  schemaEngine.createTable(tiGroup, true);
291 291  }
... ... @@ -296,7 +296,7 @@
296 296  {{code language="java"}}
297 297  @Override
298 298  public void performUpdate(ISchemaEngine schemaEngine) throws SQLException {
299 - String sql = "UPDATE "+TableDefs.TB_EXAMPLE_TABLE_NAME+" SET "+TableDefs.COL_EXAMPLE_NAME+"=?";
294 + String sql = "UPDATE "+TableDefinitions.TB_EXAMPLE_TABLE_NAME+" SET "+TableDefinitions.COL_EXAMPLE_NAME+"=?";
300 300  
301 301   PreparedStatement ps = schemaEngine.getConnection().prepareStatement(sql);
302 302  
... ... @@ -328,22 +328,22 @@
328 328  The legacy strategy is:
329 329  
330 330  (% 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
326 +* At the start of a project, create and use TableDefinitions.java
327 +* After the first commit, TableDefinitions are considered frozen, all changes go into SchemaUpdates, up to one update per source code commit
333 333  
334 334  Advantage: Rock solid.
335 335  
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.
331 +Disadvantage: No place to look for the complete current scheme, except actual databases. See //Recommendation 1// below for a workaround.
337 337  
338 338  === {{id name="HowTocreateandupdateDatabasesusingSchemaManagerandSchemaUpdateSnippets-Possiblebutdangerous:Evolving(Initial)TableList"/}}Possible but dangerous: Evolving (Initial) Table List ===
339 339  
340 -To keep the (Initial) Schema up do date, one might use this strategy:
335 +To keep the TableDefinitions up do date, one might use this strategy:
341 341  
342 342  (% 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
338 +* keep the TableDefinitions up to date, so an empty database always gets the current scheme in one shot
339 +* SchemaUpdates are only applied to existing databases
345 345  
346 -Advantage: Immediate overview over exact current scheme.
341 +Advantage: Immediate overview over current scheme.
347 347  
348 348  Disadvantage: Very real danger of messing something up, because
349 349  
... ... @@ -351,16 +351,22 @@
351 351  * schema updates have to be coded in 2 different places in 2 different ways
352 352  * the bean definition has to be maintained in 2 places but just 1
353 353  
354 -Conclusion: **DO NOT DO THIS**. This strategy may be ok in very early stages, but at some point it has to be
349 +Conclusion: DO NOT DO THIS. This strategy may be ok in very early stages, but at some point it has to be
355 355  
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)(%%) ===
351 +=== {{id name="HowTocreateandupdateDatabasesusingSchemaManagerandSchemaUpdateSnippets-Recommendation1:SplitTableDefinitionsfrominitialTableList"/}}Recommendation 1: Split TableDefinitions from initial Table List ===
357 357  
353 +If TableDefinitions (pseudo constants for table and column names) go in a dedicated pseudo class it can serve as good overview over the database structure.
354 +
355 +=== {{id name="HowTocreateandupdateDatabasesusingSchemaManagerandSchemaUpdateSnippets-Recommendation2:FreezeTableDefinition,notafterRC/1.0/GA"/}}Recommendation 2: (% style="font-size: 14.0pt;" %)Freeze Table Definition, not after RC/1.0/GA(%%) ===
356 +
358 358  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.
359 359  
360 360  (% 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!
361 361  
362 -= {{id name="HowTocreateandupdateDatabasesusingSchemaManagerandSchemaUpdateSnippets-RealworldExample"/}}Real world Example =
361 +
363 363  
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**!
363 +
365 365  
366 -(% style="font-size: 10.0pt;line-height: 13.0pt;" %)\\
365 +
366 +
367 +
Confluence.Code.ConfluencePageClass[0]
Id
... ... @@ -1,1 +1,1 @@
1 -656790
1 +656817
URL
... ... @@ -1,1 +1,1 @@
1 -https://clazzes.atlassian.net/wiki/spaces/JDBC2XML/pages/656790/How To create and update Databases using SchemaManager and SchemaUpdateSnippets
1 +https://clazzes.atlassian.net/wiki/spaces/JDBC2XML/pages/656817/How To create and update Databases using SchemaManager and SchemaUpdateSnippets