在vb.net或C＃中使用LINQ中的indexOf（）函数？

时间：2016-04-23 07:46:13

标签： c# vb.net string linq

我在数据库中有一个表，它有一个列名。当我在Grid中显示之前，我必须更改所有项目名称。我必须使用这个LINQ条款

Dim hospitalList = From l In db_Obj.VWrmz_HospitalCorrection
                       Select hospitalName = l.HOSPITAL_NAME.Substring(0,l.HOSPITAL_NAME.IndexOf("--"))

当我使用上面的代码时，我收到此错误消息：

  

LINQ to Entities无法识别方法'Int32   IndexOf（System.String，System.StringComparison）'方法，以及此方法   方法无法转换为商店表达式。

但是当我正确删除其IndexOf()工作时：

Dim hospitalList = From l In db_Obj.VWrmz_HospitalCorrection
                   Select hospitalName = l.HOSPITAL_NAME.Substring(10)

如何从我的细胞中移除这样的东西？

3 个答案:

答案 0 :(得分：1)

也许使用匿名？

Dim hospitalList = From l In db_Obj.VWrmz_HospitalCorrection
                       Select New With {.hospitalName = l.HOSPITAL_NAME.Substring(0,l.HOSPITAL_NAME.IndexOf("--"))}

答案 1 :(得分：0)

在您的错误消息中，无法识别的方法是“Int32.IndexOf”，“IndexOf”方法的调用者是“Int32”而不是“String”，您的HOSPITAL_NAME是否可能是一个数字？

如果找不到问题，你可以试试正则表达式而不是“Substring”方法，就像这样（我正在使用C＃，所以......这是c＃代码，对不起）：

Regex regex = new Regex("--.*");
var hospitalList = From l In db_Obj.VWrmz_HospitalCorrection
                   Select hospitalName = regex.Replace(l.HOSPITAL_NAME, "");

希望这可以帮助

答案 2 :(得分：0)

这是一个C＃版本。
LINQ to EF无法将mean方法转换为sql语法。您可以稍后获取数据并对其执行操作。

#!/bin/sh
    # This script can be launch using the command-line "wget https://raw.githubusercontent.com/sdenel/How-to-install-SimpleScalar-on-Ubuntu /master/Install-SimpleScalar.sh && chmod +x Install-SimpleScalar.sh && ./Install-SimpleScalar.sh"

    # This is the only line requiring root permission
   sudo apt-get install bison flex gzip gcc-multilib lib32z1 lib32ncurses5 lib32bz2-1.0 zenity xdg-utils make

    # Will install SimpleScalar in ~/SimpleScalar
    export IDIR=$HOME"/SimpleScalar"

    mkdir $IDIR
    cd $IDIR

    # A simple wget commandline would not comply with licences, so SimpleScalar has to be downloaded manually
    TEXT="Thanks to:\n-Accept the licence then download the archive file\n-Place the archive here: "$IDIR"\n-Close your web-browser"
    xdg-open http://www.simplescalar.com/agreement.php3?simplesim-3v0e.tgz &
    echo -e $TEXT
    sleep 0.5
    zenity --info --text "$TEXT" &
    read -p "Please press ENTREE once the task is done" a

    wget http://www.simplescalar.com/downloads/simpletools-2v0.tgz
    wget http://www.simplescalar.com/downloads/simpleutils-2v0.tgz

    gunzip  *.tgz
    tar -xf simpletools-*.tar
    tar -xf simpleutils-*.tar
    tar -xf simplesim-*.tar
    rm *.tar
    rm *.tgz

    ### binutils Compilation ###
    cd binutils-*
    ./configure --host=i386-pc-linux --target=sslittle-na-sstrix --with-gnu-as --with-gnu-ld --prefix=$IDIR

    # Avoiding:
    # vasprintf.c:48:3: error: invalid initializer

    sed -i -e "s/va_list ap = args;/va_list ap; va_copy(ap, args);/g" libiberty/vasprintf.c
    # Avoiding:
    # vasprintf.c:35:7: erreur: conflicting types for ‘malloc’
    sed -i -e "s/char \*malloc ();/\/\/char \*malloc ();/g" libiberty/vasprintf.c

    # Avoiding:
    # ./ldlex.l:477:7: error: 'yy_current_buffer' undeclared (first use in this function)
    sed -i -e "s/yy_current_buffer/YY_CURRENT_BUFFER/g" ld/ldlex.l

    # avoiding errors like: /usr/lib/gcc/x86_64-linux-gnu/4.6/include/varargs.h:4:2: error: #error "GCC no longer implements <varargs.h>."
    # but also: ldmisc.c:318:31: error: expected expression before ‘char’
    sed -i -e "s/varargs.h/stdarg.h/g" ld/ldmisc.c

    # Avoiding errors due to an outdated code
    # Inspired from http://zealoct.wordpress.com/2011/04/19/install-simplescalar-on-ubuntu-10-10-with-gcc-4-4/
    # avoiding: ldmisc.c:348:15: error: macro "va_start" requires 2 arguments, but only 1 given
    sed -i -e "s/  va_list arg;/\/\/  va_list arg;/g" ld/ldmisc.c
    sed -i -e "s/  va_start/\/\/  va_start/g" ld/ldmisc.c
    sed -i -e "s/  file/\/\/  file/g" ld/ldmisc.c
    sed -i -e "s/  fmt/\/\/  fmt/g" ld/ldmisc.c
    sed -i -e "s/  vfinfo/\/\/  vfinfo/g" ld/ldmisc.c
    sed -i -e "s/  va_end/\/\/  va_end/g" ld/ldmisc.c

    # Avoiding:
    # ldmisc.c:402:6: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘va_dcl’
    # ldmisc.c:344:6: error: expected declaration specifiers before ‘va_dcl’
    sed -i -e "s/(va_alist)/()/g" ld/ldmisc.c
    sed -i -e "s/     va_dcl/\/\/     va_dcl/g" ld/ldmisc.c
    sed -i -e "s/     FILE \*fp;/\/\/     FILE \*fp;/g" ld/ldmisc.c
    sed -i -e "s/     char \*fmt;/\/\/     char \*fmt;/g" ld/ldmisc.c
    sed -i -e "s/vfinfo(fp, fmt, arg)/vfinfo(FILE \*fp, char \*fmt, va_list arg)/g" ld/ldmisc.c

    # Avoiding:
    # follows non-static declaration:
    #strerror.c:467:12: error: static declaration of ‘sys_nerr’ follows non-static declaration
    # static int sys_nerr;
    #            ^
    #In file included from /usr/include/stdio.h:853:0,
    #                 from strerror.c:35:
    #/usr/include/x86_64-linux-gnu/bits/sys_errlist.h:26:12: note: previous declaration of ‘sys_nerr’ was here
    # extern int sys_nerr;
    sed -i -e "s/NEED_sys_errlist/NEED_sys_errPROTECTEDlist/g" libiberty/strerror.c
    sed -i -e "s/sys_nerr/sys_nerr_2/g" libiberty/strerror.c
    sed -i -e "s/sys_errlist/sys_errlist_2/g" libiberty/strerror.c
    sed -i -e "s/NEED_sys_errPROTECTEDlist/NEED_sys_errlist/g" libiberty/strerror.c

    make all
    make install


    cd ../simplesim*
    make config-pisa
    make
    # You can check that SimpleScalar (not the toolchain) works with the command-line:
    # ./sim-safe tests-alpha/bin/test-math


    cd ../
    cd gcc-*

    ./configure --host=i386-pc-linux --target=sslittle-na-sstrix --with-gnu-as --with-gnu-ld --prefix=$IDIR

    # Avoiding:
    # insn-output.c:676:5: error: stray ‘\’ in program
    sed -i 's/return \\"FIXME\\\\n/return \\"FIXME\\\\n\\\\/g' config/ss/ss.md
    #sed -i 's/return \"FIXME\\n/return \"FIXME\\n\\/g' insn-output.c

# Do not include LIBGCC2_INCLUDES leads to
# ./libgcc2.c:1384: stdio.h: No such file or directory
# make: *** [libgcc2.a] Error 1
# make has to be launched before to correct errors...

make LANGUAGES="c c++" CFLAGS="-O3" CC="gcc"    

# Avoiding:
# decl.c:3605:3: error: lvalue required as increment operand
sed -i -e "s/\*((void \*\*)__o->next_free)++ = ((void \*)datum);/\*((void \*\*)__o->next_free++) = ((void \*)datum);/g" obstack.h

# Avoiding:
# cxxmain.c:2978: error: conflicting types for ‘malloc’ - uniquement pour gcc 2.7

#chmod 755 cxxmain.c
#sed -i -e "s/char \* malloc ();/\/\/char \* malloc ();/g" cxxmain.c
#sed -i -e "s/char \* realloc ();/\/\/char \* realloc ();/g" cxxmain.c

# Avoiding:
# sdbout.c:57:18: fatal error: syms.h: No such file or directory
sed -i -e "s/#include <syms.h>/#include \"gsyms.h\"/g" sdbout.c

# Avoiding:
# cccp.c:194:14: error: conflicting types for ‘sys_errlist’
sed -i -e "s/extern char \*sys_errlist\[\];/\/\/extern char \*sys_errlist\[\];/g" cccp.c
# Avoiding:
# ./cp/g++.c:90:14: error: conflicting types for ‘sys_errlist’
sed -i -e "s/extern char \*sys_errlist\[\];/\/\/extern char \*sys_errlist\[\];/g" cp/g++.c
# Avoiding: 
# gcc.c:172:14: erreur: conflicting types for ‘sys_errlist’
sed -i -e "s/extern char \*sys_errlist\[\];/\/\/extern char \*sys_errlist\[\];/g" gcc.c

make LANGUAGES="c c++" CFLAGS="-O3" CC="gcc"
# If you do not uncompress simpletools at the right place, You will face:
# /usr/include/_G_config.h:53: unknown machine mode `_G_int16_t'
# /usr/include/_G_config.h:54: unknown machine mode `_G_int32_t'
# /usr/include/_G_config.h:55: unknown machine mode `_G_uint16_t'
# /usr/include/_G_config.h:56: unknown machine mode `_G_uint32_t'
make install LANGUAGES="c c++" CFLAGS="-O3" CC="gcc"

echo 'PATH='$IDIR'/bin:$PATH' >> ~/.bashrc
cd ../simplesim-*
echo 'PATH='$PWD':$PATH' >> ~/.bashrc

echo "This is it! Please restart your session in order to update your global variables."
相关问题
最新问题