だと言う

say that; state that

→ だ
phrase Very common #630
say that; state that Used after a noun or na-adjective plus だ to quote or report a statement. In actual sentences, 言う is often conjugated, as in だと言った (“said that”) or だと言っている (“is saying that”). It may also be written or pronounced as だという in some contexts.
JA: 彼は父親が病気だと言ったが、それはうそだった。
EN: He said that his father was ill, but it was a lie.

飛行機はむしろ経済的だと言う人もいる

Some people say that flying is actually more economical.

フランス語は習得容易だと言う人もいる

Some people say that French is easy to learn.

テレビは有害無益だと言う人もいる

Some people say that television is harmful and serves no useful purpose.

警部シュタイナーの友人だと言う男が来ました

A man who says he’s Inspector Steiner’s friend has come to see you.

— 甘い生活 (1960)

自殺だと言う

Are you saying it was suicide?

— マルコムX (1992)

スミスさんは自分はニューヨーク生まれだが妻は日本だと言う

Mr. Smith says that he was born in New York, but his wife is from Japan.

答えろなぜみんな僕をだと言う

Answer me—why does everyone say I’m you?

— ファイト・クラブ (1999)

彼女が貧しいからと言って不正直だと言う事にはならない

Just because she is poor doesn't mean she is dishonest.

ある人はこうだと言いまたある人はああだと言う

Some people say it's one way, while others say it's another.

公表すれば共犯だと言う

If you make it public, I'll say you're an accomplice.

— 戦争と女の顔 (2019)