Golang（带有gocql驱动程序）未返回Cassandra DB中的所有条目

I have what appears to be a strange bug in either the gocql driver for Cassandra, or in the Cassandra database itself.

I am trying to do a simple write and then read all request in two separate functions. I would expect that I would get all entries on the read all request, but I am only getting the last entry in Cassandra.

Here is how I am doing the write:

    util.CassSession, _ = util.CassCluster.CreateSession()
    defer util.CassSession.Close()
    keySpaceMeta, _ := util.CassSession.KeyspaceMetadata("platypus")
    valC, exists := keySpaceMeta.Tables["cassmessage"]

    if exists==true {
        fmt.Println("cassmessage exists!!!")
    }else{
        fmt.Println("cassmessage doesnt exist!")
    }

    if valC!=nil{
        fmt.Println("return from valC cassmessage: ", valC)
    }

    insertString:=`INSERT INTO cassmessage 
    (messagefrom, messageto, messagecontent) 
    VALUES('`+sendMsgReq.MessageFrom+`', '`
    +sendMsgReq.MessageTo+`', '`+sendMsgReq.MessageContent+`')`

    fmt.Println("insertString value: ", insertString)

    err := util.CassSession.Query(insertString).Exec()

if err != nil {
        fmt.Println("there was an error in appending data to cassmessage: ", err)
    } else {
        fmt.Println("inserted data into cassmessage successfully")
    }

the terminal output from the above:

app_1          | [17:59:43][WEBSERVER] : cassmessage exists!!!
app_1          | [17:59:43][WEBSERVER] : return from valC cassmessage:
&{platypus cassmessage    [] []  
[0xc000400140] [] map[messagefrom:0xc0004000a0 
messageto:0xc000400140 messagecontent:0xc000400000] 
[messagecontent messagefrom messageto]}
app_1          | [17:59:43][WEBSERVER] : inserted data into cassmessage successfully

I am not entirely sure what the output of valC is returning, although it appears to be some sort of memory address which is a good sign. I also see that I am not getting any error on the write exec function which is hopeful.

Here is how I am doing the read:

util.CassSession, _ = util.CassCluster.CreateSession()
defer util.CassSession.Close()
keySpaceMeta, _ := util.CassSession.KeyspaceMetadata("platypus")
valC, exists := keySpaceMeta.Tables["cassmessage"]

queryString := `SELECT messageto, messagecontent, messagefrom FROM cassmessage WHERE messagefrom='`+mailReq.Email+`'`
//returns nothing, should return many rows
queryString2 := `SELECT messageto, messagecontent, messagefrom FROM cassmessage`
//returns only last entry, should return many rows
queryString3 := `SELECT * FROM cassmessage WHERE messagefrom='`+mailReq.Email+`'`
//returns nothing, should return many rows
queryAllString := `SELECT * FROM cassmessage` 
//returns only last entry, should return many rows

var messageto string
var messagecontent string
var messagefrom string

iter := util.CassSession.Query(queryAllString).Iter()
for iter.Scan(&messageto, &messagecontent, &messagefrom) {
    fmt.Println("Iter messageto: %v", messageto)
    fmt.Println("Iter messagecontent: %v", messagecontent)
    fmt.Println("Iter messagefrom: %v", messagefrom)
}

the terminal output from above:

app_1          | [18:09:54][WEBSERVER] : Iter messageto: %v xyz@xyz.com
app_1          | [18:09:54][WEBSERVER] : Iter messagecontent: %v a
app_1          | [18:09:54][WEBSERVER] : Iter messagefrom: %v abc@abc.com

This is not what I expect, as this is the output from the read, after multiple writes to the database. If you look at comments on the various queryString values I have tried 2 of them return nothing when I expect all entries to be returned, and 2 of them only return the last write entry (they are all symmetric queries to my knowledge).

Does anyone know why I cannot return multiple entries using Iter or why my four different values on the different query strings I have tried are returning different results?

Thank you.

I maybe shouldn't, but I'm going to keep this here in case someone else runs into the same problem. I wasn't making sure that my primary key in my table was unique. Doing something like this:

util.CassSession.Query("CREATE TABLE cassmessage(" +
    "messageto text, messagefrom text, messagecontent text, uniqueID text, PRIMARY KEY (uniqueID))").Exec()

Managed to fix the issue.

Thanks to everyone who took a look and helped. Cheers!