+
−/*
+
− * This Source Code Form is subject to the terms of the Mozilla Public
+
− * License, v. 2.0.  If a copy of the MPL was not distributed with this
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− * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
− *
+
− * Copyright 2016 MonetDB B.V.
+
− */
+
−
+
−package nl.cwi.monetdb.embedded;
+
−
+
−import java.util.ArrayList;
+
−import java.util.List;
+
−
+
−/**
+
− * A single connection to a MonetDB database instance
+
− * Communication between Java and native C is done via JNI.
+
− * <br/>
+
− * <strong>Note</strong>: You can have only one Embedded MonetDB database running per JVM process.
+
− *
+
− * @author <a href="mailto:pedro.ferreira@monetdbsolutions.com">Pedro Ferreira</a>
+
− */
+
−public class MonetDBEmbeddedConnection {
+
−
+
−    private final MonetDBEmbeddedDatabase database;
+
−
+
−	private final long connectionPointer;
+
−
+
−    private final List<AbstractStatementResult> results = new ArrayList<>();
+
−
+
−	protected MonetDBEmbeddedConnection(MonetDBEmbeddedDatabase database, long connectionPointer) {
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−        this.database = database;
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−        this.connectionPointer = connectionPointer;
+
−	}
+
−
+
−    /**
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−     * Gets the current schema set on the connection.
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−     *
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−     * @return A Java String with the name of the schema
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−     * @throws MonetDBEmbeddedException If an error in the database occurred
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−     */
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−    public String getCurrentSchema() throws MonetDBEmbeddedException {
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−        QueryResultSet eqr = this.sendQuery("select current_schema from sys.var();");
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−        QueryResultSetColumn<String> col = eqr.getColumn(0);
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−        String res = col.fetchFirstNColumnValues(1)[0];
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−        eqr.close();
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−        return res;
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−    }
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−
+
−    /**
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−     * Sets the current schema on the connection.
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−     *
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−     * @param currentSchema Java String with the name of the schema
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−     * @throws MonetDBEmbeddedException If an error in the database occurred
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−     */
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−    public void setCurrentSchema(String currentSchema) throws MonetDBEmbeddedException {
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−        String valueToSubmit = "'" + currentSchema.replaceAll("\\\\", "\\\\\\\\").replaceAll("'", "\\\\'") + "';";
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−        this.sendUpdate("SET SCHEMA " + valueToSubmit).close();
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−    }
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−
+
−    /**
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−     * Begins a transaction.
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−     *
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−     * @throws MonetDBEmbeddedException If an error in the database occurred
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−     */
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−    public void startTransaction() throws MonetDBEmbeddedException {
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−        this.sendUpdate("START TRANSACTION;").close();
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−    }
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−
+
−    /**
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−     * Commits the current transaction.
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−     *
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−     * @throws MonetDBEmbeddedException If an error in the database occurred
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−     */
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−    public void commit() throws MonetDBEmbeddedException {
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−        this.sendUpdate("COMMIT;").close();
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−    }
+
−
+
−    /**
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−     * Rollbacks the current transaction.
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−     *
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−     * @throws MonetDBEmbeddedException If an error in the database occurred
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−     */
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−    public void rollback() throws MonetDBEmbeddedException {
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−        this.sendUpdate("ROLLBACK;").close();
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−    }
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−
+
−    /**
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−     * Executes a SQL query without a result set.
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−     *
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−     * @param query The SQL query string
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−     * @return The update result object
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−     * @throws MonetDBEmbeddedException If an error in the database occurred
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−     */
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−    public UpdateResultSet sendUpdate(String query) throws MonetDBEmbeddedException {
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−        if (!query.endsWith(";")) {
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−            query += ";";
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−        }
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−        UpdateResultSet res = this.sendUpdateInternal(this.connectionPointer, query, true);
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−        results.add(res);
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−        return res;
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−    }
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−
+
−    /**
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−     * Executes a SQL query without a result set asynchronously.
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−     *
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−     * @param query The SQL query string
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−     * @return The update result object
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−     * @throws MonetDBEmbeddedException If an error in the database occurred
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−     */
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−    public UpdateResultSet sendUpdateAsync(String query) throws MonetDBEmbeddedException {
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−        /* CompletableFuture.supplyAsync(() -> this.sendUpdate(query)); */
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−        throw new UnsupportedOperationException("Must wait for Java 8 :(");
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−    }
+
−
+
−    /**
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−	 * Executes a SQL query with a result set.
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−	 * 
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−	 * @param query The SQL query string
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−	 * @return The query result object
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−	 * @throws MonetDBEmbeddedException If an error in the database occurred
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−	 */
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−	public QueryResultSet sendQuery(String query) throws MonetDBEmbeddedException {
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−		if (!query.endsWith(";")) {
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−            query += ";";
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−		}
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−        QueryResultSet res = this.sendQueryInternal(this.connectionPointer, query, true);
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−        results.add(res);
+
−        return res;
+
−	}
+
−
+
−    /**
+
−     * Executes an SQL query with a result set asynchronously.
+
−     *
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−     * @param query The SQL query string
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−     * @return The query result object
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−     * @throws MonetDBEmbeddedException If an error in the database occurred
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−     */
+
−    public QueryResultSet sendQueryAsync(String query) throws MonetDBEmbeddedException {
+
−        /* CompletableFuture.supplyAsync(() -> this.sendQuery(query)); */
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−        throw new UnsupportedOperationException("Must wait for Java 8 :(");
+
−    }
+
−
+
−    /**
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−     * Creates a prepared query statement likewise the PreparedStatement in JDBC.
+
−     *
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−     * @param query The SQL query with ? indicating the parameters to replace in the query
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−     * @return An instance of EmbeddedPreparedStatement
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−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−    public EmbeddedPreparedStatement createPreparedStatement(String query) throws MonetDBEmbeddedException {
+
−        if (!query.endsWith(";")) {
+
−            query += ";";
+
−        }
+
−        return this.createPreparedStatementInternal(this.connectionPointer, query);
+
−    }
+
−
+
−    /**
+
−     * Creates a prepared query statement likewise the PreparedStatement in JDBC asynchronously.
+
−     *
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−     * @param query The SQL query with ? indicating the parameters to replace in the query
+
−     * @return An instance of EmbeddedPreparedStatement
+
−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−    public EmbeddedPreparedStatement createPreparedStatementAsync(String query) throws MonetDBEmbeddedException {
+
−        /* CompletableFuture.supplyAsync(() -> this.createPreparedStatement(query)); */
+
−        throw new UnsupportedOperationException("Must wait for Java 8 :(");
+
−    }
+
−
+
−    /*public MonetDBTable getMonetDBTable(String schemaName, String tableName) throws MonetDBEmbeddedException {
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−        MonetDBTable res = this.getMonetDBTableInternal(schemaName, tableName, this.connectionPointer);
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−        //results.add(res);
+
−        return res;
+
−    }
+
−        add the method from current schema
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−    public MonetDBTable getMonetDBTableAsync(String schema, String tableName) throws MonetDBEmbeddedException {
+
−        throw new UnsupportedOperationException("Must wait for Java 8 :(");
+
−    }*/
+
−
+
−    /**
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−     * Performs a listing of the existing tables with schemas.
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−     *
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−     * @param listSystemTables List system's tables as well (default true)
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−     * @return The query result object, {@code null} if the database is not running
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−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−    public QueryResultSet listTables(boolean listSystemTables) throws MonetDBEmbeddedException {
+
−        String query = "select schemas.name as sn, tables.name as tn from sys.tables join sys.schemas on tables.schema_id=schemas.id";
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−        if (!listSystemTables) {
+
−            query += " where tables.system=false order by sn, tn";
+
−        }
+
−        return this.sendQuery(query + ";");
+
−    }
+
−
+
−    /**
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−     * Check if a table it exists.
+
−     *
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−     * @param schemaName The schema of the table
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−     * @param tableName The name of the table
+
−     * @return If a the table exists or not
+
−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−    public boolean checkIfTableExists(String schemaName, String tableName) throws MonetDBEmbeddedException {
+
−        String query =
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−                "select schemas.name as sn, tables.name as tn from sys.tables join sys.schemas on tables.schema_id=schemas.id where tables.system=true order by sn, tn and schemas.name ='" +
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−                        schemaName + "' and tables.name ='" + tableName + "';";
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−        QueryResultSet eqr = this.sendQuery(query);
+
−        eqr.close();
+
−        return eqr.getNumberOfRows() > 0;
+
−    }
+
−
+
−    /**
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−     * Deletes a table if it exists.
+
−     *
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−     * @param schemaName The schema of the table
+
−     * @param tableName The name of the table
+
−     * @throws MonetDBEmbeddedException
+
−     */
+
−    public void removeTable(String schemaName, String tableName) throws MonetDBEmbeddedException {
+
−        String query = "drop table " + schemaName + "." + tableName + ";";
+
−        this.sendUpdate(query).close();
+
−    }
+
−
+
−    /**
+
−     * Shuts down this connection. Any pending queries connections will be immediately closed as well.
+
−     */
+
−    public void shutdownConnection() {
+
−        for(AbstractStatementResult res : this.results) {
+
−            res.close();
+
−        }
+
−        this.shutdownConnectionInternal(this.connectionPointer);
+
−        this.database.removeConnection(this);
+
−    }
+
−
+
−    /**
+
−     * Shuts down this connection asynchronously. Any pending queries connections will be immediately closed as well.
+
−     */
+
−    public void shutdownConnectionAsync() {
+
−        /* CompletableFuture.supplyAsync(() -> this.shutdownConnection()); */
+
−        throw new UnsupportedOperationException("Must wait for Java 8 :(");
+
−    }
+
−
+
−    /**
+
−     * Removes a query result from this connection.
+
−     */
+
−    protected void removeQueryResult(AbstractStatementResult res) {
+
−        this.results.remove(res);
+
−    }
+
−
+
−    private native UpdateResultSet sendUpdateInternal(long connectionPointer, String query, boolean execute)
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−            throws MonetDBEmbeddedException;
+
−
+
−    private native QueryResultSet sendQueryInternal(long connectionPointer, String query, boolean execute)
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−            throws MonetDBEmbeddedException;
+
−
+
−    private native EmbeddedPreparedStatement createPreparedStatementInternal(long connectionPointer, String query)
+
−            throws MonetDBEmbeddedException;
+
−
+
−    /*private native MonetDBTable getMonetDBTableInternal(long connectionPointer, String schemaName, String tableName)
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−            throws MonetDBEmbeddedException;*/
+
−
+
−    private native void shutdownConnectionInternal(long connectionPointer);
+
−}