Dépôt officiel du code source de l'ERP OpenConcerto

/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

 *

 * Copyright 2011 OpenConcerto, by ILM Informatique. All rights reserved.

 *

 * The contents of this file are subject to the terms of the GNU General Public License Version 3

 * only ("GPL"). You may not use this file except in compliance with the License. You can obtain a

 * copy of the License at http://www.gnu.org/licenses/gpl-3.0.html See the License for the specific

 * language governing permissions and limitations under the License.

 *

 * When distributing the software, include this License Header Notice in each file.

 */

 package org.openconcerto.sql.model;

import org.openconcerto.sql.model.SQLField.Properties;

import org.openconcerto.sql.model.SQLTable.SQLIndex;

import org.openconcerto.sql.model.graph.Link.Rule;

import org.openconcerto.sql.model.graph.TablesMap;

import org.openconcerto.sql.utils.ChangeTable;

import org.openconcerto.sql.utils.ChangeTable.ClauseType;

import org.openconcerto.sql.utils.ChangeTable.OutsideClause;

import org.openconcerto.sql.utils.SQLUtils;

import org.openconcerto.sql.utils.SQLUtils.SQLFactory;

import org.openconcerto.utils.CollectionUtils;

import org.openconcerto.utils.ListMap;

import org.openconcerto.utils.StringUtils;

import org.openconcerto.utils.Tuple2;

import org.openconcerto.utils.cc.ITransformer;

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.OutputStreamWriter;

import java.io.Reader;

import java.io.Writer;

import java.math.BigDecimal;

import java.sql.Blob;

import java.sql.Clob;

import java.sql.Connection;

import java.sql.SQLException;

import java.sql.Timestamp;

import java.util.ArrayList;

import java.util.Collections;

import java.util.Date;

import java.util.HashMap;

import java.util.IdentityHashMap;

import java.util.Iterator;

import java.util.List;

import java.util.Map;

import java.util.Map.Entry;

import java.util.Set;

import java.util.regex.Pattern;

import org.apache.commons.dbcp.DelegatingConnection;

/**

 * MySQL can enable compression with the "useCompression" connection property. Compression status

 * can be checked with "show global status like 'Compression';".

 *

 * @author Sylvain CUAZ

 */

public class SQLSyntaxMySQL extends SQLSyntax {

    final static SQLSyntax create(DBSystemRoot sysRoot) {

        final boolean noBackslashEscapes;

        if (sysRoot == null) {

            noBackslashEscapes = false;

        } else {

            final String modes = (String) sysRoot.getDataSource().executeScalar("SELECT @@global.sql_mode;");

            noBackslashEscapes = modes.contains("NO_BACKSLASH_ESCAPES");

        }

        return new SQLSyntaxMySQL(noBackslashEscapes);

    }

    static private final IdentityHashMap<String, String> DATE_SPECS;

    static private final Map<Class<?>, String> CAST_TYPES;

    static {

        DATE_SPECS = new IdentityHashMap<String, String>();

        DATE_SPECS.put(DateProp.YEAR, "%Y");

        DATE_SPECS.put(DateProp.MONTH_NAME, "%M");

        DATE_SPECS.put(DateProp.MONTH_NUMBER, "%m");

        DATE_SPECS.put(DateProp.DAY_IN_MONTH, "%d");

        DATE_SPECS.put(DateProp.DAY_NAME_IN_WEEK, "%W");

        DATE_SPECS.put(DateProp.HOUR, "%H");

        DATE_SPECS.put(DateProp.MINUTE, "%i");

        DATE_SPECS.put(DateProp.SECOND, "%S");

        DATE_SPECS.put(DateProp.MICROSECOND, "%f");

        CAST_TYPES = new HashMap<Class<?>, String>();

        CAST_TYPES.put(Short.class, "signed integer");

        CAST_TYPES.put(Integer.class, "signed integer");

        CAST_TYPES.put(Long.class, "signed integer");

        CAST_TYPES.put(BigDecimal.class, "decimal");

        CAST_TYPES.put(Timestamp.class, "datetime");

        CAST_TYPES.put(java.sql.Date.class, "date");

        CAST_TYPES.put(java.sql.Time.class, "time");

        CAST_TYPES.put(Blob.class, "binary");

        CAST_TYPES.put(String.class, "char");

    }

    private final boolean noBackslashEscapes;

    public SQLSyntaxMySQL(final boolean noBackslashEscapes) {

        super(SQLSystem.MYSQL, DATE_SPECS);

        this.noBackslashEscapes = noBackslashEscapes;

        this.typeNames.addAll(Boolean.class, "boolean", "bool", "bit");

        this.typeNames.addAll(Short.class, "smallint");

        this.typeNames.addAll(Integer.class, "integer", "int");

        this.typeNames.addAll(Long.class, "bigint");

        this.typeNames.addAll(BigDecimal.class, "decimal", "numeric");

        this.typeNames.addAll(Float.class, "float");

        this.typeNames.addAll(Double.class, "double precision", "real");

        this.typeNames.addAll(Timestamp.class, "datetime", "timestamp");

        this.typeNames.addAll(java.sql.Date.class, "date");

        this.typeNames.addAll(java.sql.Time.class, "time");

        this.typeNames.addAll(Blob.class, "blob", "tinyblob", "mediumblob", "longblob", "varbinary", "binary");

        this.typeNames.addAll(Clob.class, "text", "tinytext", "mediumtext", "longtext", "varchar", "char");

        this.typeNames.addAll(String.class, "varchar", "char");

    }

    @Override

    public final String quoteString(String s) {

        final String res = super.quoteString(s);

        if (s == null)

            return res;

        // ATTN if noBackslashEscapes is changed for the session,

        // then SQL can be injected :

        // toto \'; drop table ;

        // is quoted to :

        // 'toto \''; drop table ;'

        // and since DDL is not transactional in MySQL the table is forever dropped.

        // escape \ by replacing them with \\

        return !this.noBackslashEscapes ? SQLSyntaxPG.BACKSLASH_PATTERN.matcher(res).replaceAll(SQLSyntaxPG.TWO_BACKSLASH_REPLACEMENT) : res;

    }

    @Override

    public int getMaximumIdentifierLength() {

        // http://dev.mysql.com/doc/refman/5.7/en/identifiers.html

        return 64;

    }

    public String getIDType() {

        return " int";

    }

    @Override

    public boolean isAuto(SQLField f) {

        return "YES".equals(f.getMetadata("IS_AUTOINCREMENT"));

    }

    @Override

    public String getAuto() {

        return this.getIDType() + " AUTO_INCREMENT NOT NULL";

    }

    @Override

    protected String getAutoDateType(SQLField f) {

        return "timestamp";

    }

    @Override

    public int getMaximumVarCharLength() {

        // http://dev.mysql.com/doc/refman/5.0/en/char.html

        return (65535 - 2) / SQLSyntaxPG.MAX_BYTES_PER_CHAR;

    }

    @Override

    protected Tuple2<Boolean, String> getCast() {

        return null;

    }

    @Override

    public String cast(String expr, Class<?> javaType) {

        // MySQL doesn't use types but keywords

        return this.cast(expr, CAST_TYPES.get(javaType));

    }

    @Override

    protected boolean supportsDefault(String typeName) {

        return !typeName.contains("text") && !typeName.contains("blob");

    }

    @Override

    public String transfDefaultJDBC2SQL(SQLField f) {

        final Class<?> javaType = f.getType().getJavaType();

        String res = f.getDefaultValue();

        if (res == null)

            // either no default or NULL default

            // see http://dev.mysql.com/doc/refman/5.0/en/data-type-defaults.html

            // (works the same way for 5.1 and 6.0)

            if (Boolean.FALSE.equals(f.isNullable()))

            res = null;

            else {

            res = "NULL";

            }

        else if (javaType == String.class)

            // this will be given to other db system, so don't use base specific quoting

            res = SQLBase.quoteStringStd(res);

        // MySQL 5.0.24a puts empty strings when not specifying default

        else if (res.length() == 0)

            res = null;

        // quote neither functions nor CURRENT_TIMESTAMP

        else if (Date.class.isAssignableFrom(javaType) && !res.trim().endsWith("()") && !res.toLowerCase().contains("timestamp"))

            res = SQLBase.quoteStringStd(res);

        else if (javaType == Boolean.class)

            res = res.equals("0") ? "FALSE" : "TRUE";

        return res;

    }

    @Override

    public String getCreateTableSuffix() {

        return " ENGINE = InnoDB ";

    }

    @Override

    public String disableFKChecks(DBRoot b) {

        return "SET FOREIGN_KEY_CHECKS=0;";

    }

    @Override

    public String enableFKChecks(DBRoot b) {

        return "SET FOREIGN_KEY_CHECKS=1;";

    }

    @Override

    public String getDropFK() {

        return "DROP FOREIGN KEY ";

    }

    @Override

    protected String getRuleSQL(Rule r) {

        if (r == Rule.SET_DEFAULT)

            throw new UnsupportedOperationException(r + " isn't supported");

        return super.getRuleSQL(r);

    }

    @Override

    public String getDropConstraint() {

        // in MySQL there's only 2 types of constraints : foreign keys and unique

        // fk are handled by getDropFK(), so this is just for unique

        // in MySQL UNIQUE constraint and index are one and the same thing

        return "DROP INDEX ";

    }

    @Override

    public Map<String, Object> normalizeIndexInfo(final Map m) {

        final Map<String, Object> res = copyIndexInfoMap(m);

        final Object nonUnique = res.get("NON_UNIQUE");

        // some newer versions of MySQL now return Boolean

        res.put("NON_UNIQUE", nonUnique instanceof Boolean ? nonUnique : Boolean.valueOf((String) nonUnique));

        res.put("COLUMN_NAME", res.get("COLUMN_NAME"));

        return res;

    }

    @Override

    public String getDropIndex(String name, SQLName tableName) {

        return "DROP INDEX " + SQLBase.quoteIdentifier(name) + " on " + tableName.quote() + ";";

    }

    @Override

    protected String getCreateIndex(String cols, SQLName tableName, SQLIndex i) {

        final String method = i.getMethod() != null ? " USING " + i.getMethod() : "";

        return super.getCreateIndex(cols, tableName, i) + method;

    }

    @Override

    public boolean isUniqueException(SQLException exn) {

        final SQLException e = SQLUtils.findWithSQLState(exn);

        // 1062 is the real "Duplicate entry" error, 1305 happens when we emulate partial unique

        // constraint

        return e.getErrorCode() == 1062 || (e.getErrorCode() == 1305 && e.getMessage().contains(ChangeTable.MYSQL_FAKE_PROCEDURE + " does not exist"));

    }

    @Override

    public boolean isDeadLockException(SQLException exn) {

        return SQLUtils.findWithSQLState(exn).getErrorCode() == 1213;

    }

    @Override

    public Map<ClauseType, List<String>> getAlterField(SQLField f, Set<Properties> toAlter, String type, String defaultVal, Boolean nullable) {

        final boolean newNullable = toAlter.contains(Properties.NULLABLE) ? nullable : getNullable(f);

        final String newType = toAlter.contains(Properties.TYPE) ? type : getType(f);

        String newDef = toAlter.contains(Properties.DEFAULT) ? defaultVal : getDefault(f, newType);

        // MySQL doesn't support "NOT NULL DEFAULT NULL" so use the equivalent "NOT NULL"

        if (!newNullable && newDef != null && newDef.trim().toUpperCase().equals("NULL"))

            newDef = null;

        return ListMap.singleton(ClauseType.ALTER_COL, "MODIFY COLUMN " + f.getQuotedName() + " " + getFieldDecl(newType, newDef, newNullable));

    }

    @Override

    public String getDropTable(SQLName name, boolean ifExists, boolean restrict) {

        // doesn't support cascade

        if (!restrict)

            return null;

        else

            return super.getDropTable(name, ifExists, restrict);

    }

    @Override

    public String getDropRoot(String name) {

        return "DROP DATABASE IF EXISTS " + SQLBase.quoteIdentifier(name) + " ;";

    }

    @Override

    public String getCreateRoot(String name) {

        return "CREATE DATABASE " + SQLBase.quoteIdentifier(name) + " ;";

    }

    @Override

    protected void _storeData(final SQLTable t, final File file) throws IOException {

        checkServerLocalhost(t);

        final ListMap<String, String> charsets = new ListMap<String, String>();

        for (final SQLField f : t.getFields()) {

            final Object charset = f.getInfoSchema().get("CHARACTER_SET_NAME");

            // non string field

            if (charset != null)

                charsets.add(charset.toString(), f.getName());

        }

        if (charsets.size() > 1)

            // MySQL dumps strings in binary, so fields must be consistent otherwise the

            // file is invalid

            throw new IllegalArgumentException(t + " has more than on character set : " + charsets);

        // if no string cols there should only be values within ASCII (eg dates, ints, etc)

        final String charset = charsets.size() == 0 ? "UTF8" : charsets.keySet().iterator().next();

        final String cols = CollectionUtils.join(t.getOrderedFields(), ",", new ITransformer<SQLField, String>() {

            @Override

            public String transformChecked(SQLField input) {

                return quoteString(input.getName());

            }

        });

        final File tmp = File.createTempFile(SQLSyntaxMySQL.class.getSimpleName() + "storeData", ".txt");

        // MySQL cannot overwrite files. Also on Windows tmp is in the user profile which the

        // service cannot access ; conversely tmpdir of MySQL is not readable by normal users,

        // in that case grant traverse and write permission to MySQL (e.g. Network Service).

        tmp.delete();

        final SQLSelect sel = new SQLSelect(true).addSelectStar(t);

        // store the data in the temp file

        t.getDBSystemRoot().getDataSource().execute("SELECT " + cols + " UNION " + sel.asString() + " INTO OUTFILE " + quoteString(tmp.getAbsolutePath()) + " " + getDATA_OPTIONS() + ";");

        // then read it to remove superfluous escape char and convert to utf8

        final BufferedReader r = new BufferedReader(new InputStreamReader(new FileInputStream(tmp), charset));

        Writer w = null;

        try {

            w = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file), StringUtils.UTF8));

            normalizeData(r, w, 1000 * 1024);

        } finally {

            r.close();

            if (w != null)

                w.close();

            tmp.delete();

        }

    }

    // remove superfluous escape character

    static void normalizeData(final Reader r, final Writer w, final int bufferSize) throws IOException {

        int count;

        final char[] buf = new char[bufferSize];

        int offset = 0;

        final char[] wbuf = new char[buf.length];

        boolean wasBackslash = false;

        while ((count = r.read(buf, offset, buf.length - offset)) != -1) {

            int wbufLength = 0;

            for (int i = 0; i < offset + count; i++) {

                final char c = buf[i];

                // MySQL escapes the field delimiter (which other systems do as well)

                // but also "LINES TERMINATED BY" which others don't understand

                if (wasBackslash && c == '\n')

                    // overwrite the backslash

                    wbuf[wbufLength - 1] = c;

                else

                    wbuf[wbufLength++] = c;

                wasBackslash = c == '\\';

            }

            // the read buffer ends with a backslash, don't let it be written to w as we might

            // want to remove it

            if (wasBackslash) {

                // restore state one char before

                wbufLength--;

                wasBackslash = wbuf[wbufLength - 1] == '\\';

                buf[0] = '\\';

                offset = 1;

            } else {

                offset = 0;

            }

            w.write(wbuf, 0, wbufLength);

        }

    }

    private String getDATA_OPTIONS() {

        return "FIELDS TERMINATED BY ',' ENCLOSED BY '\"' ESCAPED BY " + quoteString("\\") + " LINES TERMINATED BY '\n' ";

    }

    @Override

    public void _loadData(final File f, final SQLTable t) {

        // we always store in utf8 regardless of the encoding of the columns

        final SQLDataSource ds = t.getDBSystemRoot().getDataSource();

        try {

            SQLUtils.executeAtomic(ds, new SQLFactory<Object>() {

                @Override

                public Object create() throws SQLException {

                    final String charsetClause;

                    final Connection conn = ((DelegatingConnection) ds.getConnection()).getInnermostDelegate();

                    if (((com.mysql.jdbc.Connection) conn).versionMeetsMinimum(5, 0, 38)) {

                        charsetClause = "CHARACTER SET utf8 ";

                    } else {

                        // variable name is in the first column

                        final String dbCharset = ds.executeA1("show variables like 'character_set_database'")[1].toString().trim().toLowerCase();

                        if (dbCharset.equals("utf8")) {

                            charsetClause = "";

                        } else {

                            throw new IllegalStateException("the database charset is not utf8 and this version doesn't support specifying another one : " + dbCharset);

                        }

                    }

                    ds.execute(t.getBase().quote("LOAD DATA LOCAL INFILE %s INTO TABLE %f ", f.getAbsolutePath(), t) + charsetClause + getDATA_OPTIONS() + " IGNORE 1 LINES;");

                    return null;

                }

            });

        } catch (Exception e) {

            throw new IllegalStateException("Couldn't load " + f + " into " + t, e);

        }

    }

    @Override

    public String getNullIsDataComparison(String x, boolean eq, String y) {

        final String nullSafe = x + " <=> " + y;

        if (eq)

            return nullSafe;

        else

            return "NOT (" + nullSafe + ")";

    }

    @Override

    public String getDayOfWeek(String sqlTS) {

        return "DAYOFWEEK(" + sqlTS + ")";

    }

    @Override

    public String getFormatTimestamp(String sqlTS, boolean basic) {

        return this.getFormatTimestamp(sqlTS, SQLBase.quoteStringStd(basic ? "%Y%m%dT%H%i%s.%f" : "%Y-%m-%dT%H:%i:%s.%f"));

    }

    @Override

    public String getFormatTimestamp(String sqlTS, String nativeFormat) {

        return "DATE_FORMAT(" + sqlTS + ", " + nativeFormat + ")";

    }

    static private final Pattern PERCENT_PATTERN = Pattern.compile("(%+)");

    @Override

    public String quoteForTimestampFormat(String text) {

        return PERCENT_PATTERN.matcher(text).replaceAll("$1$1");

    }

    @Override

    public String getConstantTableStatement(List<List<String>> rows, int colCount) {

        if (colCount < 0)

            colCount = rows.get(0).size();

        return getConstantTable(rows, null, Collections.<String> nCopies(colCount, null));

    }

    private final void getRow(StringBuilder sb, List<String> row, final int requiredColCount, List<String> columnsAlias) {

        // should be OK since requiredColCount is computed from columnsAlias in getConstantTable()

        assert columnsAlias == null || requiredColCount == columnsAlias.size();

        final int actualColCount = row.size();

        if (actualColCount != requiredColCount)

            throw new IllegalArgumentException("Wrong number of columns, should be " + requiredColCount + " but row is " + row);

        for (int i = 0; i < actualColCount; i++) {

            sb.append(row.get(i));

            if (columnsAlias != null && columnsAlias.get(i) != null) {

                sb.append(" as ");

                sb.append(SQLBase.quoteIdentifier(columnsAlias.get(i)));

            }

            if (i < actualColCount - 1)

                sb.append(", ");

        }

    }

    @Override

    public String getConstantTable(List<List<String>> rows, String alias, List<String> columnsAlias) {

        final int rowCount = rows.size();

        if (rowCount < 1)

            throw new IllegalArgumentException("Empty rows will cause a syntax error");

        final int colCount = columnsAlias.size();

        if (colCount < 1)

            throw new IllegalArgumentException("Empty columns will cause a syntax error");

        final StringBuilder sb = new StringBuilder(rows.size() * 64);

        if (alias != null)

            sb.append("( ");

        sb.append("SELECT ");

        // aliases needed only for the first row

        getRow(sb, rows.get(0), colCount, columnsAlias);

        for (int i = 1; i < rowCount; i++) {

            sb.append("\nUNION ALL\nSELECT ");

            getRow(sb, rows.get(i), colCount, null);

        }

        if (alias != null) {

            sb.append(" ) as ");

            sb.append(SQLBase.quoteIdentifier(alias));

        }

        return sb.toString();

    }

    @Override

    public String getFunctionQuery(SQLBase b, Set<String> schemas) {

        // MySQL puts the db name in schema

        return "SELECT null as \"schema\", ROUTINE_NAME as \"name\", ROUTINE_DEFINITION as \"src\" FROM \"information_schema\".ROUTINES where ROUTINE_CATALOG is null and ROUTINE_SCHEMA = '"

                + b.getMDName() + "'";

    }

    @Override

    public String getTriggerQuery(SQLBase b, TablesMap tables) {

        return "SELECT \"TRIGGER_NAME\", null as \"TABLE_SCHEMA\", EVENT_OBJECT_TABLE as \"TABLE_NAME\", ACTION_STATEMENT as \"ACTION\", null as \"SQL\" from INFORMATION_SCHEMA.TRIGGERS "

                + getMySQLTablesMapJoin(b, tables, "EVENT_OBJECT_SCHEMA", "EVENT_OBJECT_TABLE");

    }

    private String getMySQLTablesMapJoin(final SQLBase b, final TablesMap tables, final String schemaCol, final String tableCol) {

        // MySQL only has "null" schemas through JDBC

        assert tables.size() <= 1;

        // but in information_schema, the TABLE_CATALOG is always NULL and TABLE_SCHEMA has the JDBC

        // database name

        final TablesMap translated;

        if (tables.size() == 0) {

            translated = tables;

        } else {

            assert tables.keySet().equals(Collections.singleton(null)) : tables;

            translated = new TablesMap(1);

            translated.put(b.getMDName(), tables.get(null));

        }

        return getTablesMapJoin(translated, schemaCol, tableCol);

    }

    @Override

    public String getColumnsQuery(SQLBase b, TablesMap tables) {

        return "SELECT null as \"" + INFO_SCHEMA_NAMES_KEYS.get(0) + "\", \"" + INFO_SCHEMA_NAMES_KEYS.get(1) + "\", \"" + INFO_SCHEMA_NAMES_KEYS.get(2)

                + "\" , \"CHARACTER_SET_NAME\", \"COLLATION_NAME\" from INFORMATION_SCHEMA.\"COLUMNS\" " + getMySQLTablesMapJoin(b, tables, "TABLE_SCHEMA", "TABLE_NAME");

    }

    @Override

    @SuppressWarnings("unchecked")

    public List<Map<String, Object>> getConstraints(SQLBase b, TablesMap tables) throws SQLException {

        final String sel = "SELECT null as \"TABLE_SCHEMA\", c.\"TABLE_NAME\", c.\"CONSTRAINT_NAME\", tc.\"CONSTRAINT_TYPE\", \"COLUMN_NAME\", c.\"ORDINAL_POSITION\", NULL as \"DEFINITION\"\n"

                // from

                + " FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE c\n"

                // "-- sub-select otherwise at least 15s\n" +

                + "JOIN (SELECT * FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS T " + getMySQLTablesMapJoin(b, tables, "TABLE_SCHEMA", "TABLE_NAME")

                + ") tc on tc.\"TABLE_SCHEMA\" = c.\"TABLE_SCHEMA\" and tc.\"TABLE_NAME\"=c.\"TABLE_NAME\" and tc.\"CONSTRAINT_NAME\"=c.\"CONSTRAINT_NAME\"\n"

                // requested tables

                + getMySQLTablesMapJoin(b, tables, "c.TABLE_SCHEMA", "c.TABLE_NAME")

                // order

                + "order by c.\"TABLE_SCHEMA\", c.\"TABLE_NAME\", c.\"CONSTRAINT_NAME\", c.\"ORDINAL_POSITION\"";

        // don't cache since we don't listen on system tables

        final List<Map<String, Object>> res = (List<Map<String, Object>>) b.getDBSystemRoot().getDataSource().execute(sel, new IResultSetHandler(SQLDataSource.MAP_LIST_HANDLER, false));

        mergeColumnNames(res);

        return res;

    }

    static void mergeColumnNames(final List<Map<String, Object>> res) {

        final Iterator<Map<String, Object>> listIter = res.iterator();

        List<String> l = null;

        while (listIter.hasNext()) {

            final Map<String, Object> m = listIter.next();

            // don't leave the meaningless position (it will always be equal to 1)

            final int pos = ((Number) m.remove("ORDINAL_POSITION")).intValue();

            if (pos == 1) {

                l = new ArrayList<String>();

                m.put("COLUMN_NAMES", l);

            } else {

                listIter.remove();

            }

            l.add((String) m.remove("COLUMN_NAME"));

        }

    }

    @Override

    public String getDropTrigger(Trigger t) {

        return "DROP TRIGGER " + new SQLName(t.getTable().getSchema().getName(), t.getName()).quote();

    }

    @Override

    public String getUpdate(final SQLTable t, List<String> tables, Map<String, String> setPart) {

        final List<String> l = new ArrayList<String>(tables);

        l.add(0, t.getSQLName().quote());

        return CollectionUtils.join(l, ", ") + "\nSET " + CollectionUtils.join(setPart.entrySet(), ",\n", new ITransformer<Entry<String, String>, String>() {

            @Override

            public String transformChecked(Entry<String, String> input) {

                // MySQL needs to prefix the fields, since there's no designated table to update

                return t.getField(input.getKey()).getSQLName(t).quote() + " = " + input.getValue();

            }

        });

    }

    public OutsideClause getSetTableComment(final String comment) {

        return new OutsideClause() {

            @Override

            public ClauseType getType() {

                return ClauseType.OTHER;

            }

            @Override

            public String asString(SQLName tableName) {

                return "ALTER TABLE " + tableName.quote() + " COMMENT = " + SQLBase.quoteStringStd(comment) + ";";

            }

        };

    }

}