如何从SQLite中的Datetime结果列中检索日期部分？

我有一个datetime类型的列，我只想从中检索日期。有什么办法可以这样做吗

以前它是一个历元值，我把它转换成日期时间

以下是一个示例结果：

smbd|ip address|1082|ip address|"2011-04-26 18:40:34"

我尝试了以下命令，但它会产生负/零结果

SELECT DATE(datetime) from attacked_total;
SELECT STRFTIME('%Y-%m-%d', datetime) FROM attacked_total;
SELECT DATETIME('%Y-%m-%d', datetime) FROM attacked_total;
SELECT DATE('%Y-%m-%d', datetime) FROM attacked_total;

---

尝试在SQL中查找“datepart”函数的用法

像这样的方法应该会奏效：

SELECT datewithouttime as datepart(dd,datefield)+'/'+datepart(mm,datefield)+"/"+datepart(yyyy,datefield) FROM tableName

您可以使用该函数

范例

> select date('2011-04-26 18:40:34')
> 2011-04-26

你只能用strftime得到一天

> select strftime('%d', '2011-04-26 18:40:34')
> 26

这很有效

SELECT strftime('%d', '2011-04-26')

你可以得到年、月、日以及日期中的所有内容

但你必须小心如何输入这些字符串

日期的格式为

YYYY-MM-DD

，因此必须以该格式输入字符串

它也区分大小写。如果您想要一个月，那么您应该使用

%m

，因为如果您使用

%m

，它将尝试获得一分钟，如果您的日期中没有时间部分，它将抛出一个错误

---

有关更多信息，请检查。

如果您使用的是SQLite，请尝试使用此函数

strftime（“%Y”，当前\u日期）

strftime（“%m”，当前\u日期）

strftime（“%d”，当前\u日期）

strftime（“%H”，当前\u日期）

strftime（“%M”，当前\u日期）

strftime（“%S”，当前\u日期）

如果您正在使用Hibernate，请尝试在SqliteDialogue类中注册此函数

 registerFunction("year", new SQLFunctionTemplate(StandardBasicTypes.INTEGER, "abs(strftime('%Y', ?1))"));
    registerFunction("month", new SQLFunctionTemplate(StandardBasicTypes.INTEGER, "abs(strftime(strftime('%m', ?1))"));
    registerFunction("day", new SQLFunctionTemplate(StandardBasicTypes.INTEGER, "abs(strftime(strftime('%d', ?1))"));
    registerFunction("hour", new SQLFunctionTemplate(StandardBasicTypes.INTEGER, "abs(strftime(strftime('%H', ?1))"));
    registerFunction("minute", new SQLFunctionTemplate(StandardBasicTypes.INTEGER, "abs(strftime(strftime('%M', ?1))"));
    registerFunction("second", new SQLFunctionTemplate(StandardBasicTypes.INTEGER, "abs(strftime(strftime('%S', ?1))"));

如果你有什么建议的话，我就离开我的Sqlite方言课

import java.sql.SQLException;
import java.sql.Types;

import org.hibernate.JDBCException;
import org.hibernate.ScrollMode;
import org.hibernate.dialect.Dialect;
import org.hibernate.dialect.function.AbstractAnsiTrimEmulationFunction;
import org.hibernate.dialect.function.NoArgSQLFunction;
import org.hibernate.dialect.function.SQLFunction;
import org.hibernate.dialect.function.SQLFunctionTemplate;
import org.hibernate.dialect.function.StandardSQLFunction;
import org.hibernate.dialect.function.VarArgsSQLFunction;
import org.hibernate.dialect.identity.IdentityColumnSupport;
import utiles.SQLiteDialectIdentityColumnSupport;
import org.hibernate.dialect.pagination.AbstractLimitHandler;
import org.hibernate.dialect.pagination.LimitHandler;
import org.hibernate.dialect.pagination.LimitHelper;
import org.hibernate.dialect.unique.DefaultUniqueDelegate;
import org.hibernate.dialect.unique.UniqueDelegate;
import org.hibernate.engine.spi.RowSelection;
import org.hibernate.exception.DataException;
import org.hibernate.exception.JDBCConnectionException;
import org.hibernate.exception.LockAcquisitionException;
import org.hibernate.exception.spi.SQLExceptionConversionDelegate;
import org.hibernate.exception.spi.TemplatedViolatedConstraintNameExtracter;
import org.hibernate.exception.spi.ViolatedConstraintNameExtracter;
import org.hibernate.internal.util.JdbcExceptionHelper;
import org.hibernate.mapping.Column;
import org.hibernate.type.StandardBasicTypes;

/**
 * An SQL dialect for SQLite 3.
 */
public class SQLiteDialect5 extends Dialect {

    private final UniqueDelegate uniqueDelegate;

    public SQLiteDialect5() {
        registerColumnType(Types.BIT, "boolean");
        //registerColumnType(Types.FLOAT, "float");
        //registerColumnType(Types.DOUBLE, "double");
        registerColumnType(Types.DECIMAL, "decimal");
        registerColumnType(Types.CHAR, "char");
        registerColumnType(Types.LONGVARCHAR, "longvarchar");
        registerColumnType(Types.TIMESTAMP, "datetime");
        registerColumnType(Types.BINARY, "blob");
        registerColumnType(Types.VARBINARY, "blob");
        registerColumnType(Types.LONGVARBINARY, "blob");

        registerFunction("concat", new VarArgsSQLFunction(StandardBasicTypes.STRING, "", "||", ""));
        registerFunction("mod", new SQLFunctionTemplate(StandardBasicTypes.INTEGER, "?1 % ?2"));
        registerFunction("quote", new StandardSQLFunction("quote", StandardBasicTypes.STRING));
        registerFunction("random", new NoArgSQLFunction("random", StandardBasicTypes.INTEGER));
        registerFunction("round", new StandardSQLFunction("round"));
        registerFunction("substr", new StandardSQLFunction("substr", StandardBasicTypes.STRING));
        registerFunction("year", new SQLFunctionTemplate(StandardBasicTypes.INTEGER, "abs(strftime('%Y', ?1))"));
        registerFunction("month", new SQLFunctionTemplate(StandardBasicTypes.INTEGER, "abs(strftime(strftime('%m', ?1))"));
        registerFunction("day", new SQLFunctionTemplate(StandardBasicTypes.INTEGER, "abs(strftime(strftime('%d', ?1))"));
        registerFunction("hour", new SQLFunctionTemplate(StandardBasicTypes.INTEGER, "abs(strftime(strftime('%H', ?1))"));
        registerFunction("minute", new SQLFunctionTemplate(StandardBasicTypes.INTEGER, "abs(strftime(strftime('%M', ?1))"));
        registerFunction("second", new SQLFunctionTemplate(StandardBasicTypes.INTEGER, "abs(strftime(strftime('%S', ?1))"));
        registerFunction("trim", new AbstractAnsiTrimEmulationFunction() {
            @Override
            protected SQLFunction resolveBothSpaceTrimFunction() {
                return new SQLFunctionTemplate(StandardBasicTypes.STRING, "trim(?1)");
            }

            @Override
            protected SQLFunction resolveBothSpaceTrimFromFunction() {
                return new SQLFunctionTemplate(StandardBasicTypes.STRING, "trim(?2)");
            }

            @Override
            protected SQLFunction resolveLeadingSpaceTrimFunction() {
                return new SQLFunctionTemplate(StandardBasicTypes.STRING, "ltrim(?1)");
            }

            @Override
            protected SQLFunction resolveTrailingSpaceTrimFunction() {
                return new SQLFunctionTemplate(StandardBasicTypes.STRING, "rtrim(?1)");
            }

            @Override
            protected SQLFunction resolveBothTrimFunction() {
                return new SQLFunctionTemplate(StandardBasicTypes.STRING, "trim(?1, ?2)");
            }

            @Override
            protected SQLFunction resolveLeadingTrimFunction() {
                return new SQLFunctionTemplate(StandardBasicTypes.STRING, "ltrim(?1, ?2)");
            }

            @Override
            protected SQLFunction resolveTrailingTrimFunction() {
                return new SQLFunctionTemplate(StandardBasicTypes.STRING, "rtrim(?1, ?2)");
            }
        });
        uniqueDelegate = new SQLiteUniqueDelegate(this);
    }

    // database type mapping support ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    @Override
    public String getCastTypeName(int code) {
        // FIXME
        return super.getCastTypeName(code);
    }

    // IDENTITY support ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    private static final SQLiteDialectIdentityColumnSupport IDENTITY_COLUMN_SUPPORT = new SQLiteDialectIdentityColumnSupport();

    @Override
    public IdentityColumnSupport getIdentityColumnSupport() {
        return IDENTITY_COLUMN_SUPPORT;
    }

    // limit/offset support ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    private static final AbstractLimitHandler LIMIT_HANDLER = new AbstractLimitHandler() {
        @Override
        public String processSql(String sql, RowSelection selection) {
            final boolean hasOffset = LimitHelper.hasFirstRow(selection);
            return sql + (hasOffset ? " limit ? offset ?" : " limit ?");
        }

        @Override
        public boolean supportsLimit() {
            return true;
        }

        @Override
        public boolean bindLimitParametersInReverseOrder() {
            return true;
        }
    };

    @Override
    public LimitHandler getLimitHandler() {
        return LIMIT_HANDLER;
    }

    // lock acquisition support ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    @Override
    public boolean supportsLockTimeouts() {
        // may be http://sqlite.org/c3ref/db_mutex.html ?
        return false;
    }

    @Override
    public String getForUpdateString() {
        return "";
    }

    @Override
    public boolean supportsOuterJoinForUpdate() {
        return false;
    }

    /*
    @Override
  public boolean dropTemporaryTableAfterUse() {
    return true; // temporary tables are only dropped when the connection is closed. If the connection is pooled...
  }
     */
    // current timestamp support ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    @Override
    public boolean supportsCurrentTimestampSelection() {
        return true;
    }

    @Override
    public boolean isCurrentTimestampSelectStringCallable() {
        return false;
    }

    @Override
    public String getCurrentTimestampSelectString() {
        return "select current_timestamp";
    }

    // SQLException support ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    private static final int SQLITE_BUSY = 5;

    private static final int SQLITE_LOCKED = 6;

    private static final int SQLITE_IOERR = 10;

    private static final int SQLITE_CORRUPT = 11;

    private static final int SQLITE_NOTFOUND = 12;

    private static final int SQLITE_FULL = 13;

    private static final int SQLITE_CANTOPEN = 14;

    private static final int SQLITE_PROTOCOL = 15;

    private static final int SQLITE_TOOBIG = 18;

    private static final int SQLITE_CONSTRAINT = 19;

    private static final int SQLITE_MISMATCH = 20;

    private static final int SQLITE_NOTADB = 26;

    @Override
    public SQLExceptionConversionDelegate buildSQLExceptionConversionDelegate() {
        return new SQLExceptionConversionDelegate() {
            @Override
            public JDBCException convert(SQLException sqlException, String message, String sql) {
                final int errorCode = JdbcExceptionHelper.extractErrorCode(sqlException);
                if (errorCode == SQLITE_TOOBIG || errorCode == SQLITE_MISMATCH) {
                    return new DataException(message, sqlException, sql);
                } else if (errorCode == SQLITE_BUSY || errorCode == SQLITE_LOCKED) {
                    return new LockAcquisitionException(message, sqlException, sql);
                } else if ((errorCode >= SQLITE_IOERR && errorCode <= SQLITE_PROTOCOL) || errorCode == SQLITE_NOTADB) {
                    return new JDBCConnectionException(message, sqlException, sql);
                }

                // returning null allows other delegates to operate
                return null;
            }
        };
    }

    @Override
    public ViolatedConstraintNameExtracter getViolatedConstraintNameExtracter() {
        return EXTRACTER;
    }

    private static final ViolatedConstraintNameExtracter EXTRACTER = new TemplatedViolatedConstraintNameExtracter() {
        @Override
        protected String doExtractConstraintName(SQLException sqle) throws NumberFormatException {
            final int errorCode = JdbcExceptionHelper.extractErrorCode(sqle);
            if (errorCode == SQLITE_CONSTRAINT) {
                return extractUsingTemplate("constraint ", " failed", sqle.getMessage());
            }
            return null;
        }
    };

    // union subclass support ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    @Override
    public boolean supportsUnionAll() {
        return true;
    }

    // DDL support ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    @Override
    public boolean canCreateSchema() {
        return false;
    }

    @Override
    public boolean hasAlterTable() {
        // As specified in NHibernate dialect
        return false;
    }

    @Override
    public boolean dropConstraints() {
        return false;
    }

    @Override
    public boolean qualifyIndexName() {
        return false;
    }

    @Override
    public String getAddColumnString() {
        return "add column";
    }

    @Override
    public String getDropForeignKeyString() {
        throw new UnsupportedOperationException("No drop foreign key syntax supported by SQLiteDialect");
    }

    @Override
    public String getAddForeignKeyConstraintString(String constraintName,
            String[] foreignKey, String referencedTable, String[] primaryKey,
            boolean referencesPrimaryKey) {
        throw new UnsupportedOperationException("No add foreign key syntax supported by SQLiteDialect");
    }

    @Override
    public String getAddPrimaryKeyConstraintString(String constraintName) {
        throw new UnsupportedOperationException("No add primary key syntax supported by SQLiteDialect");
    }

    @Override
    public boolean supportsCommentOn() {
        return true;
    }

    @Override
    public boolean supportsIfExistsBeforeTableName() {
        return true;
    }

    /* not case insensitive for unicode characters by default (ICU extension needed)
    public boolean supportsCaseInsensitiveLike() {
    return true;
  }
     */
    @Override
    public boolean doesReadCommittedCauseWritersToBlockReaders() {
        // TODO Validate (WAL mode...)
        return true;
    }

    @Override
    public boolean doesRepeatableReadCauseReadersToBlockWriters() {
        return true;
    }

    @Override
    public boolean supportsTupleDistinctCounts() {
        return false;
    }

    @Override
    public int getInExpressionCountLimit() {
        // Compile/runtime time option: http://sqlite.org/limits.html#max_variable_number
        return 1000;
    }

    @Override
    public UniqueDelegate getUniqueDelegate() {
        return uniqueDelegate;
    }

    private static class SQLiteUniqueDelegate extends DefaultUniqueDelegate {

        public SQLiteUniqueDelegate(Dialect dialect) {
            super(dialect);
        }

        @Override
        public String getColumnDefinitionUniquenessFragment(Column column) {
            return " unique";
        }
    }

    @Override
    public String getSelectGUIDString() {
        return "select hex(randomblob(16))";
    }

    @Override
    public ScrollMode defaultScrollMode() {
        return ScrollMode.FORWARD_ONLY;
    }
}

import java.sql.SQLException；
导入java.sql.Types；
导入org.hibernate.jdbception；
导入org.hibernate.ScrollMode；
导入org.hibernate.dialogue.dialogue；
导入org.hibernate.dial.function.AbstractAnsitimemulationFunction；
导入org.hibernate.dial.function.NoArgSQLFunction；
导入org.hibernate.dial.function.SQLFunction；
导入org.hibernate.dial.function.SQLFunctionTemplate；
导入org.hibernate.dial.function.StandardSQLFunction；
导入org.hibernate.dial.function.VarArgsSQLFunction；
导入org.hibernate.dial.identity.IdentityColumnSupport；
导入utiles.sqlitediallationidentitycolumnsupport；
导入org.hibernate.dial.pagination.AbstractLimitHandler；
导入org.hibernate.dial.pagination.LimitHandler；
导入org.hibernate.dial.pagination.LimitHelper；
导入org.hibernate.dial.unique.DefaultUniqueDelegate；
导入org.hibernate.dial.unique.UniqueDelegate；
导入org.hibernate.engine.spi.RowSelection；
导入org.hibernate.exception.DataException；
导入org.hibernate.exception.JDBCConnectionException；
导入org.hibernate.exception.LockAcquisitionException；
导入org.hibernate.exception.spi.sqlexceptionConversionLegate；
导入org.hibernate.exception.spi.TemplatedViolatedConstraintNameExtracter；
导入org.hibernate.exception.spi.ViolatedConstraintNameExtractor；
导入org.hibernate.internal.util.jdbceptionHelper；
导入org.hibernate.mapping.Column；
导入org.hibernate.type.StandardBasicTypes；
/**
*SQLite 3的SQL方言。
*/
公共类SqliteDialogue 5扩展了方言{
私人最终唯一代表唯一代表；
公共SQLITe5（）{
registerColumnType（Types.BIT，“布尔”）；
//registerColumnType（Types.FLOAT，“FLOAT”）；
//registerColumnType（Types.DOUBLE，“DOUBLE”）；
registerColumnType（Types.DECIMAL，“DECIMAL”）；
registerColumnType（Types.CHAR，“CHAR”）；
registerColumnType（Types.LONGVARCHAR，“LONGVARCHAR”）；
registerColumnType（Types.TIMESTAMP，“datetime”）；
registerColumnType（Types.BINARY，“blob”）；
registerColumnType（Types.VARBINARY，“blob”）；
registerColumnType（Types.LONGVARBINARY，“blob”）；
registerFunction（“concat”，新的VarArgsSQLFunction（StandardBasicTypes.STRING，”，“| |，”，”）；
registerFunction（“mod”，新的SQLFunctionTemplate（StandardBasicTypes.INTEGER，“？1%？2”）；
registerFunction（“quote”，新的StandardSQLFunction（“quote”，StandardBasicTypes.STRING））；
registerFunction（“random”，新的NoArgSQLFunction（“random”，StandardBasicTypes.INTEGER））；
registerFunction（“round”，新标准SQLfunction（“round”）；
registerFunction（“substr”，新的StandardSQLFunction（“substr”，StandardBasicTypes.STRING））；
registerFunction（“年”，新的SQLFunctionTemplate（StandardBasicTypes.INTEGER），abs（strftime（“%Y”，1））；
registerFunction（“月”，新的SQLFunctionTemplate（StandardBasicTypes.INTEGER，“abs（strftime（strftime（“%m'，？1）））））；
registerFunction（“天”，新的SQLFunctionTemplate（StandardBasicTypes.INTEGER，“abs（strftime（strftime（“%d'，？1）））））；
registerFunction（“hour”，新的SQLFunctionTemplate（StandardBasicTypes.INTEGER，“abs（strftime（strftime（“%H”），1）））；
registerFunction（“分钟”，新的SQLFunctionTemplate（StandardBasicTypes.INTEGER，abs（strftime（strftime（“%M'，？1））））；
registerFunction（“第二个”，新的SQLFunctionTemplate（StandardBasicTypes.INTEGER，“abs（strftime（strftime（“%S'，？1）））））；
registerFunction（“trim”，新的AbstractAnsitimemulationFunction（）{
@凌驾
受保护的SQLFunction ResolveBothPaceTrimFunction（）{
返回新的SQLFunctionTemplate（StandardBasicTypes.STRING，“trim（？1）”；
}
@凌驾
受保护的SQLFunction ResolveBothPaceTrimFromFunction（）{
返回新的SQLFunctionTemplate（StandardBasicTypes.STRING，“trim（？2）”）；
}
@凌驾
受保护的SQLFunction ResolvingLeadingSpaceTrimFunction（）{
返回新的SQLFunctionTemplate（StandardBasicTypes.STRING，“ltrim（？1）”）；
}
@凌驾
受保护的SQLFunction resolveTrailingSpaceTrimFunction（）{
返回新的SQLFunctionTemplate（StandardBasicTypes.STRING，“rtrim（？1）”）；
}
@凌驾
受保护的SQLFunction resolveBothTrimFunction（）{
返回新的SQLFunctionTemplate（StandardB