svn-gvsig-desktop / trunk / org.gvsig.desktop / org.gvsig.desktop.compat.cdc / org.gvsig.fmap.dal / org.gvsig.fmap.dal.db / org.gvsig.fmap.dal.db.jdbc / src / main / java / org / gvsig / fmap / dal / store / jdbc2 / spi / operations / TableIsEmptyOperation.java @ 44058
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1 | 43020 | jjdelcerro | package org.gvsig.fmap.dal.store.jdbc2.spi.operations; |
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2 | |||
3 | import java.sql.Connection; |
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4 | import java.sql.ResultSet; |
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5 | import java.sql.SQLException; |
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6 | import java.sql.Statement; |
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7 | import org.apache.commons.lang3.StringUtils; |
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8 | import org.gvsig.fmap.dal.exception.DataException; |
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9 | import org.gvsig.fmap.dal.store.jdbc2.JDBCHelper; |
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10 | import org.gvsig.fmap.dal.store.jdbc2.spi.JDBCSQLBuilderBase; |
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11 | import org.gvsig.fmap.dal.store.jdbc.exception.JDBCSQLException; |
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12 | import org.gvsig.fmap.dal.store.jdbc2.JDBCUtils; |
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13 | 44058 | jjdelcerro | import org.gvsig.fmap.dal.store.jdbc2.OperationsFactory.TableReference; |
14 | 43020 | jjdelcerro | |
15 | public class TableIsEmptyOperation extends AbstractConnectionOperation { |
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16 | |||
17 | 44058 | jjdelcerro | private final TableReference table; |
18 | 43020 | jjdelcerro | private final String baseFilter; |
19 | private final String filter; |
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20 | |||
21 | public TableIsEmptyOperation(
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22 | JDBCHelper helper |
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23 | ) { |
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24 | 44058 | jjdelcerro | this(helper, null, null, null); |
25 | 43020 | jjdelcerro | } |
26 | |||
27 | public TableIsEmptyOperation(
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28 | JDBCHelper helper, |
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29 | 44058 | jjdelcerro | TableReference table, |
30 | 43020 | jjdelcerro | String baseFilter,
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31 | String filter
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32 | ) { |
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33 | super(helper);
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34 | 44058 | jjdelcerro | this.table = table;
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35 | 43020 | jjdelcerro | this.baseFilter = baseFilter;
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36 | this.filter = filter;
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37 | } |
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38 | |||
39 | @Override
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40 | public final Object perform(Connection conn) throws DataException { |
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41 | 44058 | jjdelcerro | return this.tableIsEmpty(conn, table, baseFilter, filter); |
42 | 43020 | jjdelcerro | } |
43 | |||
44 | public boolean tableIsEmpty(Connection conn, |
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45 | 44058 | jjdelcerro | TableReference table, |
46 | 43020 | jjdelcerro | String baseFilter,
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47 | 44058 | jjdelcerro | String filter
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48 | ) throws DataException {
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49 | 43020 | jjdelcerro | |
50 | JDBCSQLBuilderBase sqlbuilder = this.createSQLBuilder();
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51 | |||
52 | sqlbuilder.select().column().all(); |
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53 | 44058 | jjdelcerro | sqlbuilder.select().from().table() |
54 | .database(this.table.getDatabase())
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55 | .schema(this.table.getSchema())
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56 | .name(this.table.getTable());
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57 | sqlbuilder.select().from().subquery(this.table.getSubquery());
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58 | 43020 | jjdelcerro | if (!StringUtils.isEmpty(baseFilter)) {
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59 | sqlbuilder.select().where().set( sqlbuilder.custom(baseFilter) ); |
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60 | } |
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61 | if (!StringUtils.isEmpty(filter)) {
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62 | // El and() hace un set() si no hay un filtro previo
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63 | sqlbuilder.select().where().and(sqlbuilder.custom(filter)); |
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64 | } |
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65 | sqlbuilder.select().limit(1);
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66 | |||
67 | String sql = sqlbuilder.select().toString();
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68 | |||
69 | Statement st = null; |
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70 | ResultSet rs = null; |
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71 | try {
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72 | st = conn.createStatement(); |
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73 | rs = JDBCUtils.executeQuery(st, sql); |
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74 | return !rs.next();
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75 | |||
76 | } catch (SQLException ex) { |
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77 | throw new JDBCSQLException(ex); |
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78 | } finally {
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79 | JDBCUtils.closeQuietly(st); |
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80 | JDBCUtils.closeQuietly(rs); |
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81 | } |
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82 | } |
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83 | |||
84 | } |