Merge pull request #3791 from katzyn/datetime

Formatted cast of datetimes to/from character strings

h2/src/docsrc/html/changelog.html

@@ -21,6 +21,10 @@ <h1>Change Log</h1>
 
 <h2>Next Version (unreleased)</h2>
 <ul>
+<li>PR #3791: Formatted cast of datetimes to/from character strings
+</li>
+<li>Issue #3785: CSVRead: Fails to translate empty Numbers, when cells are quoted
+</li>
 <li>Issue #3762: Comparison predicates with row values don't create index conditions
 </li>
 <li>PR #3761: LAST_DAY function and other changes

h2/src/main/org/h2/api/ErrorCode.java

@@ -1140,7 +1140,7 @@ public class ErrorCode {
 
     /**
     * The error with code <code>90056</code> is thrown when trying to format a
-    * timestamp using TO_DATE and TO_TIMESTAMP  with an invalid format.
+    * timestamp using TO_DATE and TO_TIMESTAMP with an invalid format.
     */
     public static final int INVALID_TO_DATE_FORMAT = 90056;
 

h2/src/main/org/h2/command/Parser.java

@@ -5164,8 +5164,9 @@ private Expression readTermWithoutIdentifier() {
             Expression arg = readExpression();
             read(AS);
             Column column = parseColumnWithType(null);
+            Expression template = readIf("FORMAT") ? readExpression() : null;
             read(CLOSE_PAREN);
-            r = new CastSpecification(arg, column);
+            r = new CastSpecification(arg, column, template);
             break;
         }
         case CURRENT_CATALOG:
@@ -5415,13 +5416,13 @@ && equalsToken("E", name)) {
                     }
                     String time = token.value(session).getString();
                     read();
-                    return ValueExpression.get(ValueTimeTimeZone.parse(time));
+                    return ValueExpression.get(ValueTimeTimeZone.parse(time, session));
                 } else {
                     boolean without = readIf("WITHOUT", "TIME", "ZONE");
                     if (currentTokenType == LITERAL && token.value(session).getValueType() == Value.VARCHAR) {
                         String time = token.value(session).getString();
                         read();
-                        return ValueExpression.get(ValueTime.parse(time));
+                        return ValueExpression.get(ValueTime.parse(time, session));
                     } else if (without) {
                         throw getSyntaxError();
                     }
@@ -5448,7 +5449,7 @@ && equalsToken("E", name)) {
                 if (equalsToken("T", name)) {
                     String time = token.value(session).getString();
                     read();
-                    return ValueExpression.get(ValueTime.parse(time));
+                    return ValueExpression.get(ValueTime.parse(time, session));
                 } else if (equalsToken("TS", name)) {
                     String timestamp = token.value(session).getString();
                     read();

h2/src/main/org/h2/command/dml/Set.java

@@ -572,7 +572,7 @@ private static TimeZoneProvider parseTimeZone(Value v) {
             TimeZoneProvider timeZone;
             try {
                 timeZone = TimeZoneProvider.ofId(v.getString());
-            } catch (IllegalArgumentException ex) {
+            } catch (RuntimeException ex) {
                 throw DbException.getInvalidValueException("TIME ZONE", v.getTraceSQL());
             }
             return timeZone;

h2/src/main/org/h2/expression/function/CastSpecification.java

@@ -9,45 +9,81 @@
 import org.h2.expression.Expression;
 import org.h2.expression.TypedValueExpression;
 import org.h2.expression.ValueExpression;
+import org.h2.message.DbException;
 import org.h2.schema.Domain;
 import org.h2.table.Column;
+import org.h2.util.DateTimeTemplate;
+import org.h2.util.HasSQL;
+import org.h2.value.DataType;
 import org.h2.value.TypeInfo;
 import org.h2.value.Value;
 import org.h2.value.ValueNull;
+import org.h2.value.ValueVarchar;
 
 /**
  * A cast specification.
  */
-public final class CastSpecification extends Function1 {
+public final class CastSpecification extends Function1_2 {
 
     private Domain domain;
 
+    public CastSpecification(Expression arg, Column column, Expression template) {
+        super(arg, template);
+        type = column.getType();
+        domain = column.getDomain();
+    }
+
     public CastSpecification(Expression arg, Column column) {
-        super(arg);
+        super(arg, null);
         type = column.getType();
         domain = column.getDomain();
     }
 
     public CastSpecification(Expression arg, TypeInfo type) {
-        super(arg);
+        super(arg, null);
         this.type = type;
     }
 
     @Override
-    public Value getValue(SessionLocal session) {
-        Value v = arg.getValue(session).castTo(type, session);
+    protected Value getValue(SessionLocal session, Value v1, Value v2) {
+        if (v2 != null) {
+            v1 = getValueWithTemplate(v1, v2, session);
+        }
+        v1 = v1.castTo(type, session);
         if (domain != null) {
-            domain.checkConstraints(session, v);
+            domain.checkConstraints(session, v1);
         }
-        return v;
+        return v1;
+    }
+
+    private Value getValueWithTemplate(Value v, Value template, SessionLocal session) {
+        if (v == ValueNull.INSTANCE) {
+            return ValueNull.INSTANCE;
+        }
+        int valueType = v.getValueType();
+        if (DataType.isDateTimeType(valueType)) {
+            if (DataType.isCharacterStringType(type.getValueType())) {
+                return ValueVarchar.get(DateTimeTemplate.of(template.getString()).format(v), session);
+            }
+        } else if (DataType.isCharacterStringType(valueType)) {
+            if (DataType.isDateTimeType(type.getValueType())) {
+                return DateTimeTemplate.of(template.getString()).parse(v.getString(), type, session);
+            }
+        }
+        throw DbException.getUnsupportedException(
+                type.getSQL(v.getType().getSQL(new StringBuilder("CAST with template from "), HasSQL.TRACE_SQL_FLAGS)
+                        .append(" to "), HasSQL.DEFAULT_SQL_FLAGS).toString());
     }
 
     @Override
     public Expression optimize(SessionLocal session) {
-        arg = arg.optimize(session);
-        if (arg.isConstant()) {
+        left = left.optimize(session);
+        if (right != null) {
+            right = right.optimize(session);
+        }
+        if (left.isConstant() && (right == null || right.isConstant())) {
             Value v = getValue(session);
-            if (v == ValueNull.INSTANCE || canOptimizeCast(arg.getType().getValueType(), type.getValueType())) {
+            if (v == ValueNull.INSTANCE || canOptimizeCast(left.getType().getValueType(), type.getValueType())) {
                 return TypedValueExpression.get(v, type);
             }
         }
@@ -56,7 +92,8 @@ public Expression optimize(SessionLocal session) {
 
     @Override
     public boolean isConstant() {
-        return arg instanceof ValueExpression && canOptimizeCast(arg.getType().getValueType(), type.getValueType());
+        return left instanceof ValueExpression && (right == null || right.isConstant())
+                && canOptimizeCast(left.getType().getValueType(), type.getValueType());
     }
 
     private static boolean canOptimizeCast(int src, int dst) {
@@ -103,8 +140,13 @@ private static boolean canOptimizeCast(int src, int dst) {
     @Override
     public StringBuilder getUnenclosedSQL(StringBuilder builder, int sqlFlags) {
         builder.append("CAST(");
-        arg.getUnenclosedSQL(builder, arg instanceof ValueExpression ? sqlFlags | NO_CASTS : sqlFlags).append(" AS ");
-        return (domain != null ? domain : type).getSQL(builder, sqlFlags).append(')');
+        left.getUnenclosedSQL(builder, left instanceof ValueExpression ? sqlFlags | NO_CASTS : sqlFlags) //
+                .append(" AS ");
+        (domain != null ? domain : type).getSQL(builder, sqlFlags);
+        if (right != null) {
+            right.getSQL(builder.append(" FORMAT "), sqlFlags);
+        }
+        return builder.append(')');
     }
 
     @Override

h2/src/main/org/h2/expression/function/DateTimeFormatFunction.java

@@ -15,11 +15,11 @@
 import java.time.ZoneId;
 import java.time.ZoneOffset;
 import java.time.format.DateTimeFormatter;
+import java.time.format.DateTimeFormatterBuilder;
 import java.time.temporal.ChronoField;
 import java.time.temporal.TemporalAccessor;
 import java.time.temporal.TemporalQueries;
 import java.time.zone.ZoneRules;
-import java.util.LinkedHashMap;
 import java.util.Locale;
 import java.util.Objects;
 
@@ -29,6 +29,7 @@
 import org.h2.expression.TypedValueExpression;
 import org.h2.message.DbException;
 import org.h2.util.JSR310Utils;
+import org.h2.util.SmallLRUCache;
 import org.h2.value.TypeInfo;
 import org.h2.value.Value;
 import org.h2.value.ValueTime;
@@ -105,16 +106,7 @@ private static final class CacheValue {
             "FORMATDATETIME", "PARSEDATETIME" //
     };
 
-    private static final LinkedHashMap<CacheKey, CacheValue> CACHE = new LinkedHashMap<CacheKey, CacheValue>() {
-
-        private static final long serialVersionUID = 1L;
-
-        @Override
-        protected boolean removeEldestEntry(java.util.Map.Entry<CacheKey, CacheValue> eldest) {
-            return size() > 100;
-        }
-
-    };
+    private static final SmallLRUCache<CacheKey, CacheValue> CACHE = SmallLRUCache.newInstance(100);
 
     private final int function;
 
@@ -288,12 +280,10 @@ private static CacheValue getDateFormat(String format, String locale, String tim
                 synchronized (CACHE) {
                     value = CACHE.get(key);
                     if (value == null) {
-                        DateTimeFormatter df;
-                        if (locale == null) {
-                            df = DateTimeFormatter.ofPattern(format);
-                        } else {
-                            df = DateTimeFormatter.ofPattern(format, new Locale(locale));
-                        }
+                        DateTimeFormatter df = new DateTimeFormatterBuilder().parseCaseInsensitive()
+                                .appendPattern(format)
+                                .toFormatter(locale == null ? Locale.getDefault(Locale.Category.FORMAT)
+                                        : new Locale(locale));
                         ZoneId zoneId;
                         if (timeZone != null) {
                             zoneId = getZoneId(timeZone);

h2/src/main/org/h2/mode/FunctionsMSSQLServer.java

@@ -50,7 +50,8 @@ public final class FunctionsMSSQLServer extends ModeFunction {
         FUNCTIONS.put("GETDATE", new FunctionInfo("GETDATE", GETDATE, 0, Value.TIMESTAMP, false, true));
         FUNCTIONS.put("LEN", new FunctionInfo("LEN", LEN, 1, Value.INTEGER, true, true));
         FUNCTIONS.put("NEWID", new FunctionInfo("NEWID", NEWID, 0, Value.UUID, true, false));
-        FUNCTIONS.put("NEWSEQUENTIALID", new FunctionInfo("NEWSEQUENTIALID", NEWSEQUENTIALID, 0, Value.UUID, true, false));
+        FUNCTIONS.put("NEWSEQUENTIALID",
+                new FunctionInfo("NEWSEQUENTIALID", NEWSEQUENTIALID, 0, Value.UUID, true, false));
         FUNCTIONS.put("ISNULL", new FunctionInfo("ISNULL", ISNULL, 2, Value.NULL, false, true));
         FUNCTIONS.put("SCOPE_IDENTITY",
                 new FunctionInfo("SCOPE_IDENTITY", SCOPE_IDENTITY, 0, Value.NUMERIC, true, false));

h2/src/main/org/h2/res/help.csv

@@ -2864,17 +2864,59 @@ CASE WHEN A IS NULL THEN 'Null' ELSE 'Not null' END
 "
 
 "Other Grammar","Cast specification","
-CAST(value AS dataTypeOrDomain)
+CAST(value AS dataTypeOrDomain [ FORMAT templateString ])
 ","
 Converts a value to another data type. The following conversion rules are used:
 When converting a number to a boolean, 0 is false and every other value is true.
 When converting a boolean to a number, false is 0 and true is 1.
 When converting a number to a number of another type, the value is checked for overflow.
 When converting a string to binary, UTF-8 encoding is used.
 Note that some data types may need explicitly specified precision to avoid overflow or rounding.
+
+Template may only be specified for casts from datetime data types to character string data types
+and for casts from character string data types to datetime data types.
+
+'-', '.', '/', ',', '''', ';', ':' and ' ' (space) characters can be used as delimiters.
+
+Y, YY, YYY, YYYY represent last 1, 2, 3, or 4 digits of year.
+YYYY, if delimited, can also be used to parse any year, including negative years.
+When a year is parsed with Y, YY, or YYY pattern missing leading digits are filled using digits from the current year.
+
+RR and RRRR have the same meaning as YY and YYYY for formatting.
+When a year is parsed with RR, the resulting year is within current year - 49 years and current year + 50 years in H2,
+other database systems may use different range of years.
+
+MM represent a month.
+
+DD represent a day of month.
+
+DDD represent a day of year, if this pattern in specified, MM and DD may not be specified.
+
+HH24 represent an hour (from 0 to 23).
+
+HH and HH12 represent an hour (from 1 to 12), this pattern may only be used together with A.M. or P.M. pattern.
+These patterns may not be used together with HH24.
+
+MI represent minutes.
+
+SS represent seconds of minute.
+
+SSSSS represent seconds of day, this pattern may not be used together with HH24, HH (HH12), A.M. (P.M.), MI or SS pattern.
+
+FF1, FF2, ..., FF9 represent fractional seconds.
+
+TZH, TZM and TZH represent hours, minutes and seconds of time zone offset.
+
+Multiple patterns for the same datetime field may not be specified.
+
+If year is not specified, current year is used. If month is not specified, current month is used. If day is not specified, 1 is used.
+
+If some fields of time or time zone are not specified, 0 is used.
+
 ","
 CAST(NAME AS INT);
-CAST(TIMESTAMP '2010-01-01 10:40:00.123456' AS TIME(6))
+CAST(TIMESTAMP '2010-01-01 10:40:00.123456' AS TIME(6));
+CAST('12:00:00 P.M.' AS TIME FORMAT 'HH:MI:SS A.M.');
 "
 
 "Other Grammar","Cipher","
@@ -5958,6 +6000,8 @@ If TIMESTAMP WITH TIME ZONE is passed and timeZoneString is specified,
 the timestamp is converted to the specified time zone and its UTC value is preserved.
 
 This method returns a string.
+
+See also [cast specification](https://h2database.com/html/grammar.html#cast_specification).
 ","
 CALL FORMATDATETIME(TIMESTAMP '2001-02-03 04:05:06',
     'EEE, d MMM yyyy HH:mm:ss z', 'en', 'GMT')
@@ -6011,6 +6055,8 @@ y year, M month, d day, H hour, m minute, s second.
 For details of the format, see ""java.time.format.DateTimeFormatter"".
 
 If timeZoneString is specified, it is used as default.
+
+See also [cast specification](https://h2database.com/html/grammar.html#cast_specification).
 ","
 CALL PARSEDATETIME('Sat, 3 Feb 2001 03:05:06 GMT',
     'EEE, d MMM yyyy HH:mm:ss z', 'en', 'GMT')

h2/src/main/org/h2/tools/Csv.java

@@ -555,11 +555,11 @@ public Object[] readRow() throws SQLException {
                     }
                 }
                 if (i < row.length) {
-                    // Empty Strings should be NULL 
-                    // in order to prevent conversion of zero-length String 
+                    // Empty Strings should be NULL
+                    // in order to prevent conversion of zero-length String
                     // to Number
-                    row[i++] = v!=null && v.length() > 0 
-                            ? v 
+                    row[i++] = v!=null && v.length() > 0
+                            ? v
                             : null;
                 }
                 if (endOfLine) {