LIKE: the escape mechanism can now be disable using ESCAPE ''.

The default escape character can be changed using the system property h2.defaultEscape.

h2/src/docsrc/help/help.csv

@@ -1344,11 +1344,16 @@ compare { {{ALL|ANY|SOME}(select)} | operand }
 | [NOT] LIKE operand [ESCAPE string]
 | [NOT] REGEXP operand
 ","
-The right hand side of a condition. When comparing with LIKE, the wildcards
-characters are _ (any one character) and % (any characters). The database uses
-an index when comparing with LIKE except if the operand starts with a wildcard.
-When comparing with REGEXP, regular expression matching is used. See Java
-Matcher.find for details.
+The right hand side of a condition. 
+
+When comparing with LIKE, the wildcards characters are _ (any one character) 
+and % (any characters). The database uses an index when comparing with LIKE 
+except if the operand starts with a wildcard. To search for the characters % and
+_, the characters need to be escaped. The default escape character is \ (backslash). 
+To select no escape character, use ESCAPE '' (empty string).
+
+When comparing with REGEXP, regular expression matching is used. 
+See Java Matcher.find for details.
 ","
 LIKE 'Jo%'
 "

h2/src/docsrc/html/changelog.html

@@ -18,7 +18,10 @@ Change Log
 <h1>Change Log</h1>
 
 <h2>Next Version (unreleased)</h2>
-<ul><li>Views using functions were not re-evaluated when necessary.
+<ul><li>LIKE: the escape mechanism can now be disable using ESCAPE ''.
+    The default escape character can be changed using the system property h2.defaultEscape.
+    The default is still '\' (as in MySQL and PostgreSQL).
+</li><li>Views using functions were not re-evaluated when necessary.
 </li><li>Improved MySQL compatibility for SHOW COLUMNS.
 </li><li>Improved PostgreSQL compatibility for timestamp literals with timezone.
 </li><li>Sergi Vladykin translated the error messages to Russian. Thanks a lot!

h2/src/docsrc/html/roadmap.html

@@ -438,6 +438,7 @@ See also <a href="build.html#providing_patches">Providing Patches</a>.
 </li><li>Support =ANY(array) as in PostgreSQL.
 </li><li>IBM DB2 compatibility: support PREVIOUS VALUE FOR sequence.
 </li><li>MySQL compatibility: alter table add index i(c), add constraint c foreign key(c) references t(c);
+</li><li>Compatibility: use different LIKE ESCAPE characters depending on the mode (disable for Derby, HSQLDB, DB2, Oracle).
 </li></ul>
 
 <h2>Not Planned</h2>

h2/src/main/org/h2/command/ddl/CreateUser.java

@@ -48,7 +48,7 @@ public class CreateUser extends DefineCommand {
     }
 
     private char[] getCharArray(Expression e) throws SQLException {
-        return e.getValue(session).getString().toCharArray();
+        return e.optimize(session).getValue(session).getString().toCharArray();
     }
 
     private byte[] getByteArray(Expression e) throws SQLException {
@@ -74,11 +74,13 @@ public class CreateUser extends DefineCommand {
         user.setComment(comment);
         if (hash != null && salt != null) {
             user.setSaltAndHash(getByteArray(salt), getByteArray(hash));
-        } else {
+        } else if (password != null) {
             SHA256 sha = new SHA256();
             char[] passwordChars = getCharArray(password);
             byte[] userPasswordHash = sha.getKeyPasswordHash(userName, passwordChars);
             user.setUserPasswordHash(userPasswordHash);
+        } else {
+            throw Message.throwInternalError();
         }
         db.addDatabaseObject(session, user);
         return 0;

h2/src/main/org/h2/constant/SysProperties.java

@@ -179,6 +179,13 @@ public class SysProperties {
      */
     public static final String CLIENT_TRACE_DIRECTORY = getStringSetting("h2.clientTraceDirectory", "trace.db/");
 
+    /**
+     * System property <code>h2.defaultEscape</code> (default: \).<br />
+     * The default escape character for LIKE comparisons. To select no escape
+     * character, use an empty string.
+     */
+    public static final Character DEFAULT_ESCAPE_CHAR = getEscapeChar(getStringSetting("h2.defaultEscape", "\\"));
+
     /**
      * System property <code>h2.defaultMaxOperationMemory</code> (default:
      * 100000).<br />
@@ -730,4 +737,8 @@ public class SysProperties {
         return getBooleanSetting(H2_PAGE_STORE, false);
     }
 
+    private static Character getEscapeChar(String s) {
+        return s == null || s.length() == 0 ? null : s.charAt(0);
+    }
+
 }

h2/src/main/org/h2/engine/Constants.java

@@ -147,11 +147,6 @@ public class Constants {
      */
     public static final int DEFAULT_DATA_PAGE_SIZE = 512;
 
-    /**
-     * The default escape character for LIKE comparisons.
-     */
-    public static final char DEFAULT_ESCAPE_CHAR = '\\';
-
     /**
      * If the HTTP server should allow connections from other computers by
      * default.

h2/src/main/org/h2/expression/CompareLike.java

@@ -11,7 +11,7 @@ import java.util.regex.Pattern;
 import java.util.regex.PatternSyntaxException;
 
 import org.h2.constant.ErrorCode;
-import org.h2.engine.Constants;
+import org.h2.constant.SysProperties;
 import org.h2.engine.Session;
 import org.h2.index.IndexCondition;
 import org.h2.message.Message;
@@ -112,14 +112,16 @@ public class CompareLike extends Condition {
         return this;
     }
 
-    private char getEscapeChar(Value e) {
+    private Character getEscapeChar(Value e) {
         if (e == null) {
-            return Constants.DEFAULT_ESCAPE_CHAR;
+            return SysProperties.DEFAULT_ESCAPE_CHAR;
         }
         String es = e.getString();
-        char esc;
-        if (es == null || es.length() == 0) {
-            esc = Constants.DEFAULT_ESCAPE_CHAR;
+        Character esc;
+        if (es == null) {
+            esc = SysProperties.DEFAULT_ESCAPE_CHAR;
+        } else if (es.length() == 0) {
+            esc = null;
         } else {
             esc = es.charAt(0);
         }
@@ -274,7 +276,7 @@ public class CompareLike extends Condition {
         return compareAt(value, 0, 0, value.length());
     }
 
-    private void initPattern(String p, char escapeChar) throws SQLException {
+    private void initPattern(String p, Character escape) throws SQLException {
         if (regexp) {
             patternString = p;
             try {
@@ -301,12 +303,12 @@ public class CompareLike extends Condition {
         for (int i = 0; i < len; i++) {
             char c = p.charAt(i);
             int type;
-            if (escapeChar == c) {
+            if (escape != null && escape == c) {
                 if (i >= len - 1) {
                     throw Message.getSQLException(ErrorCode.LIKE_ESCAPE_ERROR_1, StringUtils.addAsterisk(p, i));
                 }
                 c = p.charAt(++i);
-                if (c != '_' && c != '%' && c != escapeChar) {
+                if (c != '_' && c != '%' && c != escape) {
                     throw Message.getSQLException(ErrorCode.LIKE_ESCAPE_ERROR_1, StringUtils.addAsterisk(p, i));
                 }
                 type = MATCH;

h2/src/main/org/h2/jdbc/JdbcDatabaseMetaData.java

@@ -155,9 +155,9 @@ public class JdbcDatabaseMetaData extends TraceObject implements DatabaseMetaDat
                     + "TYPE_NAME REF_GENERATION, "
                     + "SQL "
                     + "FROM INFORMATION_SCHEMA.TABLES "
-                    + "WHERE TABLE_CATALOG LIKE ? "
-                    + "AND TABLE_SCHEMA LIKE ? "
-                    + "AND TABLE_NAME LIKE ? "
+                    + "WHERE TABLE_CATALOG LIKE ? ESCAPE '\\' "
+                    + "AND TABLE_SCHEMA LIKE ? ESCAPE '\\' "
+                    + "AND TABLE_NAME LIKE ? ESCAPE '\\' "
                     + "AND (" + tableType + ") "
                     + "ORDER BY TABLE_TYPE, TABLE_SCHEMA, TABLE_NAME");
             prep.setString(1, getCatalogPattern(catalogPattern));
@@ -248,10 +248,10 @@ public class JdbcDatabaseMetaData extends TraceObject implements DatabaseMetaDat
                     + "SOURCE_DATA_TYPE, "
                     + "CASE WHEN SEQUENCE_NAME IS NULL THEN 'NO' ELSE 'YES' END IS_AUTOINCREMENT "
                     + "FROM INFORMATION_SCHEMA.COLUMNS "
-                    + "WHERE TABLE_CATALOG LIKE ? "
-                    + "AND TABLE_SCHEMA LIKE ? "
-                    + "AND TABLE_NAME LIKE ? "
-                    + "AND COLUMN_NAME LIKE ? "
+                    + "WHERE TABLE_CATALOG LIKE ? ESCAPE '\\' "
+                    + "AND TABLE_SCHEMA LIKE ? ESCAPE '\\' "
+                    + "AND TABLE_NAME LIKE ? ESCAPE '\\' "
+                    + "AND COLUMN_NAME LIKE ? ESCAPE '\\' "
                     + "ORDER BY TABLE_SCHEM, TABLE_NAME, ORDINAL_POSITION");
             prep.setString(1, getCatalogPattern(catalogPattern));
             prep.setString(2, getSchemaPattern(schemaPattern));
@@ -327,8 +327,8 @@ public class JdbcDatabaseMetaData extends TraceObject implements DatabaseMetaDat
                     + "FILTER_CONDITION, "
                     + "SORT_TYPE "
                     + "FROM INFORMATION_SCHEMA.INDEXES "
-                    + "WHERE TABLE_CATALOG LIKE ? "
-                    + "AND TABLE_SCHEMA LIKE ? "
+                    + "WHERE TABLE_CATALOG LIKE ? ESCAPE '\\' "
+                    + "AND TABLE_SCHEMA LIKE ? ESCAPE '\\' "
                     + "AND (" + uniqueCondition + ") "
                     + "AND TABLE_NAME = ? "
                     + "ORDER BY NON_UNIQUE, TYPE, TABLE_SCHEM, INDEX_NAME, ORDINAL_POSITION");
@@ -377,8 +377,8 @@ public class JdbcDatabaseMetaData extends TraceObject implements DatabaseMetaDat
                     + "ORDINAL_POSITION KEY_SEQ, "
                     + "IFNULL(CONSTRAINT_NAME, INDEX_NAME) PK_NAME "
                     + "FROM INFORMATION_SCHEMA.INDEXES "
-                    + "WHERE TABLE_CATALOG LIKE ? "
-                    + "AND TABLE_SCHEMA LIKE ? "
+                    + "WHERE TABLE_CATALOG LIKE ? ESCAPE '\\' "
+                    + "AND TABLE_SCHEMA LIKE ? ESCAPE '\\' "
                     + "AND TABLE_NAME = ? "
                     + "AND PRIMARY_KEY = TRUE "
                     + "ORDER BY COLUMN_NAME");
@@ -554,9 +554,9 @@ public class JdbcDatabaseMetaData extends TraceObject implements DatabaseMetaDat
                     + "RETURNS_RESULT PROCEDURE_TYPE, "
                     + "ALIAS_NAME SPECIFIC_NAME "
                     + "FROM INFORMATION_SCHEMA.FUNCTION_ALIASES "
-                    + "WHERE ALIAS_CATALOG LIKE ? "
-                    + "AND ALIAS_SCHEMA LIKE ? "
-                    + "AND ALIAS_NAME LIKE ? "
+                    + "WHERE ALIAS_CATALOG LIKE ? ESCAPE '\\' "
+                    + "AND ALIAS_SCHEMA LIKE ? ESCAPE '\\' "
+                    + "AND ALIAS_NAME LIKE ? ESCAPE '\\' "
                     + "ORDER BY PROCEDURE_SCHEM, PROCEDURE_NAME, NUM_INPUT_PARAMS");
             prep.setString(1, getCatalogPattern(catalogPattern));
             prep.setString(2, getSchemaPattern(schemaPattern));
@@ -638,10 +638,10 @@ public class JdbcDatabaseMetaData extends TraceObject implements DatabaseMetaDat
                     + "'YES' IS_NULLABLE, "
                     + "ALIAS_NAME SPECIFIC_NAME "
                     + "FROM INFORMATION_SCHEMA.FUNCTION_COLUMNS "
-                    + "WHERE ALIAS_CATALOG LIKE ? "
-                    + "AND ALIAS_SCHEMA LIKE ? "
-                    + "AND ALIAS_NAME LIKE ? "
-                    + "AND COLUMN_NAME LIKE ? "
+                    + "WHERE ALIAS_CATALOG LIKE ? ESCAPE '\\' "
+                    + "AND ALIAS_SCHEMA LIKE ? ESCAPE '\\' "
+                    + "AND ALIAS_NAME LIKE ? ESCAPE '\\' "
+                    + "AND COLUMN_NAME LIKE ? ESCAPE '\\' "
                     + "ORDER BY PROCEDURE_SCHEM, PROCEDURE_NAME, ORDINAL_POSITION");
             prep.setString(1, getCatalogPattern(catalogPattern));
             prep.setString(2, getSchemaPattern(schemaPattern));
@@ -780,10 +780,10 @@ public class JdbcDatabaseMetaData extends TraceObject implements DatabaseMetaDat
                     + "PRIVILEGE_TYPE PRIVILEGE, "
                     + "IS_GRANTABLE "
                     + "FROM INFORMATION_SCHEMA.COLUMN_PRIVILEGES "
-                    + "WHERE TABLE_CATALOG LIKE ? "
-                    + "AND TABLE_SCHEMA LIKE ? "
+                    + "WHERE TABLE_CATALOG LIKE ? ESCAPE '\\' "
+                    + "AND TABLE_SCHEMA LIKE ? ESCAPE '\\' "
                     + "AND TABLE_NAME = ? "
-                    + "AND COLUMN_NAME LIKE ? "
+                    + "AND COLUMN_NAME LIKE ? ESCAPE '\\' "
                     + "ORDER BY COLUMN_NAME, PRIVILEGE");
             prep.setString(1, getCatalogPattern(catalogPattern));
             prep.setString(2, getSchemaPattern(schemaPattern));
@@ -837,9 +837,9 @@ public class JdbcDatabaseMetaData extends TraceObject implements DatabaseMetaDat
                     + "PRIVILEGE_TYPE PRIVILEGE, "
                     + "IS_GRANTABLE "
                     + "FROM INFORMATION_SCHEMA.TABLE_PRIVILEGES "
-                    + "WHERE TABLE_CATALOG LIKE ? "
-                    + "AND TABLE_SCHEMA LIKE ? "
-                    + "AND TABLE_NAME LIKE ? "
+                    + "WHERE TABLE_CATALOG LIKE ? ESCAPE '\\' "
+                    + "AND TABLE_SCHEMA LIKE ? ESCAPE '\\' "
+                    + "AND TABLE_NAME LIKE ? ESCAPE '\\' "
                     + "ORDER BY TABLE_SCHEM, TABLE_NAME, PRIVILEGE");
             prep.setString(1, getCatalogPattern(catalogPattern));
             prep.setString(2, getSchemaPattern(schemaPattern));
@@ -897,8 +897,8 @@ public class JdbcDatabaseMetaData extends TraceObject implements DatabaseMetaDat
                     +" INFORMATION_SCHEMA.COLUMNS C "
                     + "WHERE C.TABLE_NAME = I.TABLE_NAME "
                     + "AND C.COLUMN_NAME = I.COLUMN_NAME "
-                    + "AND C.TABLE_CATALOG LIKE ? "
-                    + "AND C.TABLE_SCHEMA LIKE ? "
+                    + "AND C.TABLE_CATALOG LIKE ? ESCAPE '\\' "
+                    + "AND C.TABLE_SCHEMA LIKE ? ESCAPE '\\' "
                     + "AND C.TABLE_NAME = ? "
                     + "AND I.PRIMARY_KEY = TRUE "
                     + "ORDER BY SCOPE");
@@ -1019,8 +1019,8 @@ public class JdbcDatabaseMetaData extends TraceObject implements DatabaseMetaDat
                     + "PK_NAME, "
                     + "DEFERRABILITY "
                     + "FROM INFORMATION_SCHEMA.CROSS_REFERENCES "
-                    + "WHERE FKTABLE_CATALOG LIKE ? "
-                    + "AND FKTABLE_SCHEMA LIKE ? "
+                    + "WHERE FKTABLE_CATALOG LIKE ? ESCAPE '\\' "
+                    + "AND FKTABLE_SCHEMA LIKE ? ESCAPE '\\' "
                     + "AND FKTABLE_NAME = ? "
                     + "ORDER BY PKTABLE_CAT, PKTABLE_SCHEM, PKTABLE_NAME, FK_NAME, KEY_SEQ");
             prep.setString(1, getCatalogPattern(catalogPattern));
@@ -1089,8 +1089,8 @@ public class JdbcDatabaseMetaData extends TraceObject implements DatabaseMetaDat
                     + "PK_NAME, "
                     + "DEFERRABILITY "
                     + "FROM INFORMATION_SCHEMA.CROSS_REFERENCES "
-                    + "WHERE PKTABLE_CATALOG LIKE ? "
-                    + "AND PKTABLE_SCHEMA LIKE ? "
+                    + "WHERE PKTABLE_CATALOG LIKE ? ESCAPE '\\' "
+                    + "AND PKTABLE_SCHEMA LIKE ? ESCAPE '\\' "
                     + "AND PKTABLE_NAME = ? "
                     + "ORDER BY FKTABLE_CAT, FKTABLE_SCHEM, FKTABLE_NAME, FK_NAME, KEY_SEQ");
             prep.setString(1, getCatalogPattern(catalogPattern));
@@ -1169,11 +1169,11 @@ public class JdbcDatabaseMetaData extends TraceObject implements DatabaseMetaDat
                     + "PK_NAME, "
                     + "DEFERRABILITY "
                     + "FROM INFORMATION_SCHEMA.CROSS_REFERENCES "
-                    + "WHERE PKTABLE_CATALOG LIKE ? "
-                    + "AND PKTABLE_SCHEMA LIKE ? "
+                    + "WHERE PKTABLE_CATALOG LIKE ? ESCAPE '\\' "
+                    + "AND PKTABLE_SCHEMA LIKE ? ESCAPE '\\' "
                     + "AND PKTABLE_NAME = ? "
-                    + "AND FKTABLE_CATALOG LIKE ? "
-                    + "AND FKTABLE_SCHEMA LIKE ? "
+                    + "AND FKTABLE_CATALOG LIKE ? ESCAPE '\\' "
+                    + "AND FKTABLE_SCHEMA LIKE ? ESCAPE '\\' "
                     + "AND FKTABLE_NAME = ? "
                     + "ORDER BY FKTABLE_CAT, FKTABLE_SCHEM, FKTABLE_NAME, FK_NAME, KEY_SEQ");
             prep.setString(1, getCatalogPattern(primaryCatalogPattern));
@@ -1421,13 +1421,15 @@ public class JdbcDatabaseMetaData extends TraceObject implements DatabaseMetaDat
     }
 
     /**
-     * Returns the default escape character for LIKE.
+     * Returns the default escape character for DatabaseMetaData search
+     * patterns.
      *
-     * @return the character '\'
+     * @return the default escape character (always '\', independent on the
+     *         mode)
      */
     public String getSearchStringEscape() {
         debugCodeCall("getSearchStringEscape");
-        return "" + Constants.DEFAULT_ESCAPE_CHAR;
+        return "\\";
     }
 
     /**

h2/src/test/org/h2/test/TestAll.java

@@ -295,15 +295,6 @@ java org.h2.test.TestAll timer
 
 /*
 
-LIKE: Use no default escape character, except for PostgreSQL and MySQL compatibility
-See DatabaseMetaData.getSearchStringEscape
-PostgreSQL: select no escape character by writing ESCAPE ''
-drop table test;
-create table test(id int);
-insert into test values(1);
-select * from test where '\' like '\' escape '';
-select * from test where '\' like '\';
-
 page store: TestBtreeIndex
 
 better document that ddl statements commit
@@ -355,10 +346,10 @@ kill -9 `jps -l | grep "org.h2.test.TestAll" | cut -d " " -f 1`
             test.runTests();
             TestPerformance.main(new String[]{ "-init", "-db", "1"});
 
-//            System.setProperty(SysProperties.H2_PAGE_STORE, "false");
-//            test.pageStore = false;
-//            test.runTests();
-//            TestPerformance.main(new String[]{ "-init", "-db", "1"});
+            System.setProperty(SysProperties.H2_PAGE_STORE, "false");
+            test.pageStore = false;
+            test.runTests();
+            TestPerformance.main(new String[]{ "-init", "-db", "1"});
         }
         System.out.println(TestBase.formatTime(System.currentTimeMillis() - time) + " total");
     }

h2/src/test/org/h2/test/testSimple.in.txt

+select 1 from dual where '\' like '\' escape '';
+> 1;
 select left(timestamp '2001-02-03 08:20:31+04', 4);
 > 2001;