Mercurial > hg > monetdb-java
view src/main/java/nl/cwi/monetdb/embedded/tables/MonetDBTable.java @ 52:5f12b8a08204 embedded
Static implementation for the Embedded Database, removed unused code.
author | Pedro Ferreira <pedro.ferreira@monetdbsolutions.com> |
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date | Thu, 17 Nov 2016 16:09:13 +0100 (2016-11-17) |
parents | c592d8a72627 |
children | 6617eaf808cb |
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package nl.cwi.monetdb.embedded.tables; import nl.cwi.monetdb.embedded.env.MonetDBEmbeddedException; import nl.cwi.monetdb.embedded.mapping.AbstractResultTable; import nl.cwi.monetdb.embedded.env.MonetDBEmbeddedConnection; import nl.cwi.monetdb.embedded.mapping.MonetDBRow; import nl.cwi.monetdb.embedded.mapping.MonetDBToJavaMapping; import nl.cwi.monetdb.embedded.resultset.QueryResultSet; import nl.cwi.monetdb.embedded.resultset.QueryResultSetColumn; /** * Java representation of a MonetDB table. It's possible to perform several CRUD operations using the respective * provided interfaces. * * @author <a href="mailto:pedro.ferreira@monetdbsolutions.com">Pedro Ferreira</a> */ public class MonetDBTable extends AbstractResultTable { private final String tableSchema; private final String tableName; protected MonetDBTable(MonetDBEmbeddedConnection connection, String tableSchema, String tableName) { super(connection); this.tableSchema = tableSchema; this.tableName = tableName; } @Override public native int getNumberOfColumns(); /** * Gets the current number of rows in the table, or -1 if an error in the database has occurred. * * @return The number of rows in the table. */ @Override public int getNumberOfRows() { int res; try { String query = "SELECT COUNT(*) FROM " + this.getTableSchema() + "." + this.getTableName() + ";"; QueryResultSet eqr = this.getConnection().sendQuery(query); QueryResultSetColumn<Long> eqc = eqr.getColumnByIndex(0); res = eqc.fetchFirstNColumnValues(1)[0].intValue(); eqr.close(); } catch (MonetDBEmbeddedException ex) { res = -1; } return res; } @Override public native String[] getColumnNames(); @Override public native String[] getColumnTypes(); @Override public native MonetDBToJavaMapping[] getMappings(); @Override public native int[] getColumnDigits(); @Override public native int[] getColumnScales(); /** * Gets the table schema name. * * @return The table schema name */ public String getTableSchema() { return this.tableSchema; } /** * Gets the table name. * * @return The table name */ public String getTableName() { return this.tableName; } /** * Gets the columns nullable indexes as an array. * * @return The columns nullable indexes as an array */ public native boolean[] getColumnNullableIndexes(); /** * Gets the columns default values in an array. * * @return The columns default values in an array */ public native String[] getColumnDefaultValues(); /** * Gets a column metadata by index. * * @param index The column index (starting from 0) * @return The column metadata, {@code null} if index not in bounds */ public native MonetDBTableColumn getColumnMetadataByIndex(int index); /** * Gets a column metadata by name. * * @param name The column name * @return The column metadata, {@code null} if not found */ public native MonetDBTableColumn getColumnMetadataByName(String name); /** * Gets all columns metadata. * * @return An array instance of columns metadata */ public native MonetDBTableColumn[] getAllColumnsMetadata(); /** * Private method to check the limits of iteration. * * @param iterator The iterator to check * @return An integer array with the limits fixed */ private int[] prepareIterator(IMonetDBTableBaseIterator iterator) { int[] res = {iterator.getFirstRowToIterate(), iterator.getLastRowToIterate()}; if(res[1] < res[0]) { int aux = res[0]; res[0] = res[1]; res[0] = aux; } if (res[0] < 1) { res[0] = 1; } int numberOfRows = this.getNumberOfRows(); if (res[1] >= numberOfRows) { res[1] = numberOfRows; } return res; } /** * Iterate over the table using a {@link IMonetDBTableCursor} instance. * * @param cursor The iterator with the business logic * @return The number of rows iterated * @throws MonetDBEmbeddedException If an error in the database occurred */ public int iterateTable(IMonetDBTableCursor cursor) throws MonetDBEmbeddedException { int[] limits = this.prepareIterator(cursor); int res = 0, total = limits[1] - limits[0] + 1; String query = new StringBuffer("SELECT * FROM ").append(this.getTableSchema()).append(".").append(this.getTableName()) .append(" LIMIT ").append(total).append(" OFFSET ").append(limits[0] - 1).append(";").toString(); QueryResultSet eqr = this.getConnection().sendQuery(query); MonetDBRow[] array = eqr.fetchAllRowValues().getAllRows(); eqr.close(); Object[][] data = new Object[eqr.getNumberOfRows()][this.getNumberOfColumns()]; for(int i = 0 ; i < eqr.getNumberOfRows() ; i++) { data[i] = array[i].getAllColumns(); } RowIterator ri = new RowIterator(this, data, limits[0], limits[1]); while(ri.tryContinueIteration()) { cursor.processNextRow(ri); res++; } return res; } /** * Appends new rows to the table. As MonetDB's storage is column-wise, the method * {@link nl.cwi.monetdb.embedded.tables.MonetDBTable#appendColumns(Object[][]) appendColumns} is preferable * over this one. * * @param data An array of rows to append * @return The number of rows appended * @throws MonetDBEmbeddedException If an error in the database occurred */ public int appendRows(Object[][] data) throws MonetDBEmbeddedException { int numberOfRows = data.length, numberOfColumns = this.getNumberOfColumns(); if(numberOfRows == 0) { throw new ArrayStoreException("Appending 0 rows?"); } Object[][] transposed = new Object[numberOfColumns][numberOfRows]; for (int i = 0; i < numberOfRows; i++) { if(data[i].length != numberOfColumns) { throw new ArrayStoreException("The values array at row " + i + " differs from the number of columns!"); } for (int j = 0; j < numberOfColumns; j++) { transposed[j][i] = data[i][j]; } } return this.appendColumns(transposed); } /** * Appends new rows to the table asynchronously. * * @param rows An array of rows to append * @return The number of rows appended * @throws MonetDBEmbeddedException If an error in the database occurred */ /*public CompletableFuture<Integer> appendRowsAsync(Object[][] rows) throws MonetDBEmbeddedException { return CompletableFuture.supplyAsync(() -> this.appendRows(schemaName, tableName)); }*/ /** * Appends new rows to the table column-wise. As MonetDB's storage is column-wise, this method is preferable over * {@link nl.cwi.monetdb.embedded.tables.MonetDBTable#appendRows(Object[][]) appendRows} method. * * @param data An array of columns to append * @return The number of rows appended * @throws MonetDBEmbeddedException If an error in the database occurred */ public int appendColumns(Object[][] data) throws MonetDBEmbeddedException { MonetDBToJavaMapping[] mappings = this.getMappings(); int numberOfRowsToInsert = data[0].length, numberOfColumns = mappings.length; if (data.length != numberOfColumns) { throw new ArrayStoreException("The number of columns differs from the table's number of columns!"); } if(numberOfRowsToInsert == 0) { throw new ArrayStoreException("Appending 0 rows?"); } for (int i = 0; i < numberOfColumns; i++) { if(data[i].length != numberOfRowsToInsert) { throw new ArrayStoreException("The number of rows in each column is not consistent!"); } } Class[] jClasses = new Class[mappings.length]; int[] javaIndexes = new int[mappings.length]; for (int i = 0; i < mappings.length; i++) { jClasses[i] = mappings[i].getJavaClass(); javaIndexes[i] = mappings[i].ordinal(); } return this.appendColumnsInternal(jClasses, javaIndexes, data, numberOfRowsToInsert); } /* * Appends new rows to the table column-wise and asynchronously. * * @param data An array of columns to append * @return The number of rows appended * @throws MonetDBEmbeddedException If an error in the database occurred */ /*public CompletableFuture<Integer> appendColumnsAsync(Object[][] data) throws MonetDBEmbeddedException { return CompletableFuture.supplyAsync(() -> this.appendColumns(schemaName, tableName)); }*/ @Override protected void closeImplementation() {} private native int appendColumnsInternal(Class[] jClasses, int[] javaIndexes, Object[][] data, int numberOfRows) throws MonetDBEmbeddedException; }